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1.  Persistent pain in a community-based sample of children and adolescents: Sex differences in psychological constructs 
The prevalence of persistent and recurrent pain among children and adolescents has important economic, social and psychological repercussions. The impact of chronic pain in children extends beyond the affected individuals – more than one-third of parents of children with pain report clinically significant levels of stress and depression. Although many pain-related psychological factors have been examined in chronic pediatric pain populations, much of that research involved clinical samples. Community-based research, however, is necessary to uncover the way pain is experienced by youth, regardless of whether treatment is sought or is available. This study aimed to ascertain the lifetime prevalence of pediatric pain in a Canadian community-based sample, and to explore age and sex differences in children who report persistent pain and those who do not with respect to several constructs believed to play important roles in the development and maintenance of persistent pain.
BACKGROUND:
Very few studies have investigated the psychological factors associated with the pain experiences of children and adolescents in community samples.
OBJECTIVES:
To examine the lifetime prevalence of, and psychological variables associated with, persistent pain in a community sample of children and adolescents, and to explore differences according to sex, age and pain history.
METHODS:
Participants completed the Childhood Anxiety Sensitivity Index (CASI), the Child Pain Anxiety Symptoms Scale (CPASS), the Multidimensional Anxiety Scale for Children-10 (MASC-10), the Pain Catastrophizing Scale for Children (PCS-C) and a pain history questionnaire that assessed chronicity and pain frequency. After research ethics board approval, informed consent/assent was obtained from 1022 individuals recruited to participate in a study conducted at the Ontario Science Centre (Toronto, Ontario).
RESULTS:
Of the 1006 participants (54% female, mean [± SD] age 11.6±2.7 years) who provided complete data, 27% reported having experienced pain that lasted for three months or longer. A 2×2×2 (pain history, age and sex) multivariate ANOVA was conducted, with the total scores on the CASI, the CPASS, the MASC-10 and the PCS-C as dependent variables. Girls with a history of persistent pain expressed higher levels of anxiety sensitivity (P<0.001) and pain catastrophizing (P<0.001) than both girls without a pain history and boys regardless of pain history. This same pattern of results was found for anxiety and pain anxiety in the older, but not the younger, age group.
CONCLUSIONS:
Boys and girls appear to differ in terms of how age and pain history relate to the expression of pain-related psychological variables. Given the prevalence of persistent pain found in the study, more research is needed regarding the developmental implications of persistent pain in childhood and adolescence.
PMCID: PMC3206778  PMID: 22059200
Children; Persistent pain; Psychosocial factors; Sex differences
2.  Parent and child anxiety sensitivity: Relationship to children’s experimental pain responsivity 
Anxiety sensitivity (AS) or fear of anxiety sensations has been linked to childhood learning history for somatic symptoms, suggesting that parental AS may impact children’s responses to pain. Using structural equation modeling (SEM), we tested a conceptual model in which parent AS predicted child AS, which in turn predicted a hypothesized latent construct consisting of children’s pain intensity ratings for three laboratory pain tasks (cold pressor, thermal heat and pressure). This conceptual model was tested in 211 non-clinical parent-child pairs (104 girls, mean age = 12.4 years; 178 mothers). Our model was supported in girls only indicating that the sex of the child moderated the hypothesized relationships. Thus, parent AS was related to child laboratory pain intensity via its contribution to child AS in girls but not in boys. In girls, 42% of the effect of parent AS on laboratory pain intensity was explained via child AS. In boys, there was no clear link between parent AS and child AS, although child AS was predictive of experimental pain intensity across sex. Our results are consistent with the notion that parent AS may operate via healthy girls’ own fear of anxiety symptoms to influence their responses to laboratory pain stimuli.
Perspective-The present study highlights sex differences in the links among parent and child anxiety sensitivity (AS; fear of anxiety sensations) and children’s experimental pain responses. Among girls, childhood learning history related to somatic symptoms may be a particularly salient factor in the development of AS and pain responsivity.
doi:10.1016/j.jpain.2005.12.004
PMCID: PMC1540407  PMID: 16632321
anxiety sensitivity; laboratory pain; children; adolescents; parent; sex differences
3.  Neuroimaging for the Evaluation of Chronic Headaches 
Executive Summary
Objective
The objectives of this evidence based review are:
i) To determine the effectiveness of computed tomography (CT) and magnetic resonance imaging (MRI) scans in the evaluation of persons with a chronic headache and a normal neurological examination.
ii) To determine the comparative effectiveness of CT and MRI scans for detecting significant intracranial abnormalities in persons with chronic headache and a normal neurological exam.
iii) To determine the budget impact of CT and MRI scans for persons with a chronic headache and a normal neurological exam.
Clinical Need: Condition and Target Population
Headaches disorders are generally classified as either primary or secondary with further sub-classifications into specific headache types. Primary headaches are those not caused by a disease or medical condition and include i) tension-type headache, ii) migraine, iii) cluster headache and, iv) other primary headaches, such as hemicrania continua and new daily persistent headache. Secondary headaches include those headaches caused by an underlying medical condition. While primary headaches disorders are far more frequent than secondary headache disorders, there is an urge to carry out neuroimaging studies (CT and/or MRI scans) out of fear of missing uncommon secondary causes and often to relieve patient anxiety.
Tension type headaches are the most common primary headache disorder and migraines are the most common severe primary headache disorder. Cluster headaches are a type of trigeminal autonomic cephalalgia and are less common than migraines and tension type headaches. Chronic headaches are defined as headaches present for at least 3 months and lasting greater than or equal to 15 days per month. The International Classification of Headache Disorders states that for most secondary headaches the characteristics of the headache are poorly described in the literature and for those headache disorders where it is well described there are few diagnostically important features.
The global prevalence of headache in general in the adult population is estimated at 46%, for tension-type headache it is 42% and 11% for migraine headache. The estimated prevalence of cluster headaches is 0.1% or 1 in 1000 persons. The prevalence of chronic daily headache is estimated at 3%.
Neuroimaging
Computed Tomography
Computed tomography (CT) is a medical imaging technique used to aid diagnosis and to guide interventional and therapeutic procedures. It allows rapid acquisition of high-resolution three-dimensional images, providing radiologists and other physicians with cross-sectional views of a person’s anatomy. CT scanning poses risk of radiation exposure. The radiation exposure from a conventional CT scanner may emit effective doses of 2-4mSv for a typical head CT.
Magnetic Resonance Imaging
Magnetic resonance imaging (MRI) is a medical imaging technique used to aid diagnosis but unlike CT it does not use ionizing radiation. Instead, it uses a strong magnetic field to image a person’s anatomy. Compared to CT, MRI can provide increased contrast between the soft tissues of the body. Because of the persistent magnetic field, extra care is required in the magnetic resonance environment to ensure that injury or harm does not come to any personnel while in the environment.
Research Questions
What is the effectiveness of CT and MRI scanning in the evaluation of persons with a chronic headache and a normal neurological examination?
What is the comparative effectiveness of CT and MRI scanning for detecting significant intracranial abnormality in persons with chronic headache and a normal neurological exam?
What is the budget impact of CT and MRI scans for persons with a chronic headache and a normal neurological exam.
Research Methods
Literature Search
Search Strategy
A literature search was performed on February 18, 2010 using OVID MEDLINE, MEDLINE In-Process and Other Non-Indexed Citations, EMBASE, the Cumulative Index to Nursing & Allied Health Literature (CINAHL), the Cochrane Library, and the International Agency for Health Technology Assessment (INAHTA) for studies published from January, 2005 to February, 2010. Abstracts were reviewed by a single reviewer and, for those studies meeting the eligibility criteria full-text articles were obtained. Reference lists were also examined for any additional relevant studies not identified through the search. Articles with an unknown eligibility were reviewed with a second clinical epidemiologist and then a group of epidemiologists until consensus was established.
Inclusion Criteria
Systematic reviews, randomized controlled trials, observational studies
Outpatient adult population with chronic headache and normal neurological exam
Studies reporting likelihood ratio of clinical variables for a significant intracranial abnormality
English language studies
2005-present
Exclusion Criteria
Studies which report outcomes for persons with seizures, focal symptoms, recent/new onset headache, change in presentation, thunderclap headache, and headache due to trauma
Persons with abnormal neurological examination
Case reports
Outcomes of Interest
Primary Outcome
Probability for intracranial abnormality
Secondary Outcome
Patient relief from anxiety
System service use
System costs
Detection rates for significant abnormalities in MRI and CT scans
Summary of Findings
Effectiveness
One systematic review, 1 small RCT, and 1 observational study met the inclusion and exclusion criteria. The systematic review completed by Detsky, et al. reported the likelihood ratios of specific clinical variables to predict significant intracranial abnormalities. The RCT completed by Howard et al., evaluated whether neuroimaging persons with chronic headache increased or reduced patient anxiety. The prospective observational study by Sempere et al., provided evidence for the pre-test probability of intracranial abnormalities in persons with chronic headache as well as minimal data on the comparative effectiveness of CT and MRI to detect intracranial abnormalities.
Outcome 1: Pre-test Probability.
The pre-test probability is usually related to the prevalence of the disease and can be adjusted depending on the characteristics of the population. The study by Sempere et al. determined the pre-test probability (prevalence) of significant intracranial abnormalities in persons with chronic headaches defined as headache experienced for at least a 4 week duration with a normal neurological exam. There is a pre-test probability of 0.9% (95% CI 0.5, 1.4) in persons with chronic headache and normal neurological exam. The highest pre-test probability of 5 found in persons with cluster headaches. The second highest, that of 3.7, was reported in persons with indeterminate type headache. There was a 0.75% rate of incidental findings.
Likelihood ratios for detecting a significant abnormality
Clinical findings from the history and physical may be used as screening test to predict abnormalities on neuroimaging. The extent to which the clinical variable may be a good predictive variable can be captured by reporting its likelihood ratio. The likelihood ratio provides an estimate of how much a test result will change the odds of having a disease or condition. The positive likelihood ratio (LR+) tells you how much the odds of having the disease increases when a test is positive. The negative likelihood ratio (LR-) tells you how much the odds of having the disease decreases when the test is negative.
Detsky et al., determined the likelihood ratio for specific clinical variable from 11 studies. There were 4 clinical variables with both statistically significant positive and negative likelihood ratios. These included: abnormal neurological exam (LR+ 5.3, LR- 0.72), undefined headache (LR+ 3.8, LR- 0.66), headache aggravated by exertion or valsalva (LR+ 2.3, LR- 0.70), and headache with vomiting (LR+ 1.8, and LR- 0.47). There were two clinical variables with a statistically significant positive likelihood ratio and non significant negative likelihood ratio. These included: cluster-type headache (LR+ 11, LR- 0.95), and headache with aura (LR+ 12.9, LR- 0.52). Finally, there were 8 clinical variables with both statistically non significant positive and negative likelihood ratios. These included: headache with focal symptoms, new onset headache, quick onset headache, worsening headache, male gender, headache with nausea, increased headache severity, and migraine type headache.
Outcome 2: Relief from Anxiety
Howard et al. completed an RCT of 150 persons to determine if neuroimaging for headaches was anxiolytic or anxiogenic. Persons were randomized to receiving either an MRI scan or no scan for investigation of their headache. The study population was stratified into those persons with a Hospital Anxiety and Depression scale (HADS) > 11 (the high anxiety and depression group) and those < 11 (the low anxiety and depression) so that there were 4 groups:
Group 1: High anxiety and depression, no scan group
Group 2: High anxiety and depression, scan group
Group 3: Low anxiety and depression, no scan group
Group 4: Low anxiety and depression, scan group
Anxiety
There was no evidence for any overall reduction in anxiety at 1 year as measured by a visual analogue scale of ‘level of worry’ when analysed by whether the person received a scan or not. Similarly, there was no interaction between anxiety and depression status and whether a scan was offered or not on patient anxiety. Anxiety did not decrease at 1 year to any statistically significant degree in the high anxiety and depression group (HADS positive) compared with the low anxiety and depression group (HADS negative).
There are serious methodological limitations in this study design which may have contributed to these negative results. First, when considering the comparison of ‘scan’ vs. ‘no scan’ groups, 12 people (16%) in the ‘no scan group’ actually received a scan within the follow up year. If indeed scanning does reduce anxiety then this contamination of the ‘no scan’ group may have reduced the effect between the groups results resulting in a non significant difference in anxiety scores between the ‘scanned’ and the ‘no scan’ group. Second, there was an inadequate sample size at 1 year follow up in each of the 4 groups which may have contributed to a Type II statistical error (missing a difference when one may exist) when comparing scan vs. no scan by anxiety and depression status. Therefore, based on the results and study limitations it is inconclusive as to whether scanning reduces anxiety.
Outcome 3: System Services
Howard et al., considered services used and system costs a secondary outcome. These were determined by examining primary care case notes at 1 year for consultation rates, symptoms, further investigations, and contact with secondary and tertiary care.
System Services
The authors report that the use of neurologist and psychiatrist services was significantly higher for those persons not offered as scan, regardless of their anxiety and depression status (P<0.001 for neurologist, and P=0.033 for psychiatrist)
Outcome 4: System Costs
System Costs
There was evidence of statistically significantly lower system costs if persons with high levels of anxiety and depression (Hospital Anxiety and Depression Scale score >11) were provided with a scan (P=0.03 including inpatient costs, and 0.047 excluding inpatient costs).
Comparative Effectiveness of CT and MRI Scans
One study reported the detection rate for significant intracranial abnormalities using CT and MRI. In a cohort of 1876 persons with a non acute headache defined as any type of headache that had begun at least 4 weeks before enrolment Sempere et al. reported that the detection rate was 19/1432 (1.3%) using CT and 4/444 (0.9%) using MRI. Of 119 normal CT scans 2 (1.7%) had significant intracranial abnormality on MRI. The 2 cases were a small meningioma, and an acoustic neurinoma.
Summary
The evidence presented can be summarized as follows:
Pre-test Probability
Based on the results by Sempere et al., there is a low pre-test probability for intracranial abnormalities in persons with chronic headaches and a normal neurological exam (defined as headaches experiences for a minimum of 4 weeks). The Grade quality of evidence supporting this outcome is very low.
Likelihood Ratios
Based on the systematic review by Detsky et al., there is a statistically significant positive and negative likelihood ratio for the following clinical variables: abnormal neurological exam, undefined headache, headache aggravated by exertion or valsalva, headache with vomiting. Grade quality of evidence supporting this outcome is very low.
Based on the systematic review by Detsky et al. there is a statistically significant positive likelihood ratio but non statistically significant negative likelihood ratio for the following clinical variables: cluster headache and headache with aura. The Grade quality of evidence supporting this outcome is very low.
Based on the systematic review by Detsky et al., there is a non significant positive and negative likelihood ratio for the following clinical variables: headache with focal symptoms, new onset headache, quick onset headache, worsening headache, male gender, headache with nausea, increased headache severity, migraine type headache. The Grade quality of evidence supporting this outcome is very low.
Relief from Anxiety
Based on the RCT by Howard et al., it is inconclusive whether neuroimaging scans in persons with a chronic headache are anxiolytic. The Grade quality of evidence supporting this outcome is low.
System Services
Based on the RCT by Howard et al. scanning persons with chronic headache regardless of their anxiety and/or depression level reduces service use. The Grade quality of evidence is low.
System Costs
Based on the RCT by Howard et al., scanning persons with a score greater than 11 on the High Anxiety and Depression Scale reduces system costs. The Grade quality of evidence is moderate.
Comparative Effectiveness of CT and MRI Scans
There is sparse evidence to determine the relative effectiveness of CT compared with MRI scanning for the detection of intracranial abnormalities. The Grade quality of evidence supporting this is very low.
Economic Analysis
Ontario Perspective
Volumes for neuroimaging of the head i.e. CT and MRI scans, from the Ontario Health Insurance Plan (OHIP) data set were used to investigate trends in the province for Fiscal Years (FY) 2004-2009.
Assumptions were made in order to investigate neuroimaging of the head for the indication of headache. From the literature, 27% of all CT and 13% of all MRI scans for the head were assumed to include an indication of headache. From that same retrospective chart review and personal communication with the author 16% of CT scans and 4% of MRI scans for the head were for the sole indication of headache. From the Ministry of Health and Long-Term Care (MOHLTC) wait times data, 73% of all CT and 93% of all MRI scans in the province, irrespective of indication were outpatient procedures.
The expenditure for each FY reflects the volume for that year and since volumes have increased in the past 6 FYs, the expenditure has also increased with a pay-out reaching 3.0M and 2.8M for CT and MRI services of the head respectively for the indication of headache and a pay-out reaching 1.8M and 0.9M for CT and MRI services of the head respectively for the indication of headache only in FY 08/09.
Cost per Abnormal Finding
The yield of abnormal finding for a CT and MRI scan of the head for the indication of headache only is 2% and 5% respectively. Based on these yield a high-level estimate of the cost per abnormal finding with neuroimaging of the head for headache only can be calculated for each FY. In FY 08/09 there were 37,434 CT and 16,197 MRI scans of the head for headache only. These volumes would generate a yield of abnormal finding of 749 and 910 with a CT scan and MRI scan respectively. The expenditure for FY 08/09 was 1.8M and 0.9M for CT and MRI services respectively. Therefore the cost per abnormal finding would be $2,409 for CT and $957 for MRI. These cost per abnormal finding estimates were limited because they did not factor in comparators or the consequences associated with an abnormal reading or FNs. The estimates only consider the cost of the neuroimaging procedure and the yield of abnormal finding with the respective procedure.
PMCID: PMC3377587  PMID: 23074404
4.  Anxiety sensitivity, fear of pain and pain-related disability in children and adolescents with chronic pain 
BACKGROUND:
Converging lines of evidence suggest that anxiety sensitivity and fear of pain may be important vulnerability factors in the development of avoidance behaviours and disability in adults with chronic pain. However, these factors have not been evaluated in children with chronic pain.
OBJECTIVES:
To examine the relationships among anxiety sensitivity, fear of pain and pain-related disability in children and adolescents with chronic pain.
METHODS:
An interview and five questionnaires (Childhood Anxiety Sensitivity Index, Pain Anxiety Symptoms Scale, Functional Disability Inventory, Multidimensional Anxiety Scale for Children, and Reynolds Child or Adolescent Depression Scale) were administered to 21 children and adolescents eight to 17 years of age (mean ± SD 14.24±2.21 years) who continued to experience pain an average of three years after discharge from a specialized pain clinic for children.
RESULTS:
Anxiety sensitivity accounted for 38.6% of the variance in fear of pain (F[1,20]=11.30; P=0.003) and fear of pain accounted for 39.9% of the variance in pain-related disability (F[1,20]=11.95; P=0.003), but anxiety sensitivity was not significantly related to pain disability (R2=0.09; P>0.05).
CONCLUSIONS:
These findings indicate that children with high levels of anxiety sensitivity had a higher fear of pain, which, in turn, was linked to increased pain disability. The results of this study suggest that anxiety sensitivity and fear of pain may play important and distinct roles in the processes that maintain chronic pain and pain-related disability in children.
PMCID: PMC2670737  PMID: 18080045
Anxiety sensitivity; Children; Chronic pain; Disability; Fear of pain
5.  Relationships among Anxious Symptomatology, Anxiety Sensitivity and Laboratory Pain Responsivity in Children 
Cognitive behaviour therapy  2006;35(4):207-215.
Existing laboratory-based research in adult samples has suggested that anxiety sensitivity (AS) increases an individual’s propensity to experience pain-related anxiety which in turn enhances pain responsivity. Such relationships have not been examined in younger populations. Thus, the present study used structural equation modeling (SEM) to test a conceptual model in which AS would evidence an indirect relationship with pain intensity via its contribution to state-specific anticipatory anxiety in relation to a variety of laboratory pain tasks (cold pressor, thermal heat, and pressure pain) in 234 healthy children (116 girls; mean age = 12.6 years, range = 8–18 years). The model further hypothesized that existing anxious symptomatology would demonstrate a direct relationship with pain intensity. Results of the SEM supported the proposed conceptual model with the total indirect effect of AS accounting for 29% of the variance in laboratory pain intensity via its effects on pain-related anticipatory anxiety. AS did not however, evidence a direct relationship with pain intensity. Anxious symptomatology on the other hand, demonstrated a significant direct effect on pain intensity, accounting for 15% of variance. The combined effects of AS, anxiety symptoms, and anticipatory anxiety together explained 62% of the variance in pain intensity. These relationships did not differ for boys and girls indicating no moderating effect of sex in the proposed model. The present results support the potential benefit of assessing both AS and anxiety symptoms in children prior to undergoing painful stimulation.
doi:10.1080/16506070600898272
PMCID: PMC1783843  PMID: 17189238
children; adolescents; anxiety; anxiety sensitivity; laboratory pain; experimental pain; pain intensity
6.  Sex Differences in the Association Between Cortisol Concentrations and Laboratory Pain Responses in Healthy Children 
Gender medicine  2009;6(Suppl 2):193-207.
Background
Research in adult populations has highlighted sex differences in cortisol concentrations and laboratory pain responses, with men exhibiting higher cortisol concentrations and reduced pain responses compared with women. Yet, less is known about the relationship of cortisol concentrations to pain in children.
Objective
This study examined associations between sex, cortisol, and pain responses to laboratory pain tasks in children.
Methods
Salivary cortisol samples from subjects aged 8 to 18 years were obtained at baseline after entering the laboratory (SCb), after the completion of all pain tasks (SC1), and at the end of the session (SC2), 20 minutes later. Blood cortisol samples were also taken after completion of the pain tasks (BC1) and at the end of the session (BC2), 20 minutes later. Subjects completed 3 counterbalanced laboratory pain tasks: pressure, heat, and cold pressor tasks. Pain measures included pain tolerance, and self-reported pain intensity and unpleasantness for all 3 tasks.
Results
The study included 235 healthy children and adolescents (119 boys, 116 girls; mean age, 12.7 years; range, 8–18 years; 109 [46.4%] were in early puberty; 94 [40.0%] white). Salivary and blood cortisol levels were highly correlated with each other. Salivary cortisol levels for the total sample and for boys and girls declined significantly from SCb to SC1 (P < 0.01), although there were no significant changes from SC1 to SC2. No significant sex differences in salivary or blood cortisol levels were evident at any assessment point. Separate examination of the cortisol–laboratory pain response relationships by sex (controlling for age and time of day) suggested different sex-specific patterns. Higher cortisol levels were associated with lower pain reactivity (ie, increased pressure tolerance) among boys compared with girls at SC1, SC2, and BC1 (SC1: r = 0.338, P = 0.003; SC2: r = 0.271, P = 0.020; and BC1: r = 0.261, P = 0.026). However, higher cortisol levels were related to higher pain response (ie, increased cold intensity [BC2: r = 0.229, P = 0.048] and unpleasantness [BC1: r = 0.237, P = 0.041]) in girls compared with boys.
Conclusions
These findings suggest important sex differences in cortisol–pain relationships in children and adolescents. Cortisol levels were positively associated with increased pain tolerance in boys and increased pain sensitivity in girls.
doi:10.1016/j.genm.2009.03.001
PMCID: PMC3486740  PMID: 19406369
pain; children; cortisol; sex differences
7.  Anxiety sensitivity and health-related quality of life in children with chronic pain 
Anxiety sensitivity (AS), or the fear of anxiety sensations has been shown to independently predict poorer health-related quality of life (HRQOL) in adults with chronic pain. Specifically, AS was found to contribute to decrements in psychological well-being and social functioning but not to decrements in physical functioning. Existing studies have not examined the relationship between AS and HRQOL in children with chronic pain. The present study used multivariate regression analysis to test the association between AS and self-reported HRQOL in 87 children (62 girls; mean age = 14.4 years ± 2.3) presenting for treatment at a tertiary, multidisciplinary clinic specializing in pediatric chronic pain. After controlling for key sociodemographic and pain-related characteristics, higher AS was associated with poorer perceived general and mental health, greater impairment in family activities, lower self-esteem, increased behavior problems, and more social/academic limitations due to emotional problems. AS accounted for 4% – 28% of incremental variance in these HRQOL domains above and beyond the demographic and pain-related variables. However, AS was not significantly associated with physical functioning or with academic/social limitations due to physical health. Additional research is required to delineate possible mechanisms by which AS may influence certain aspects of children's HRQOL but not others.
Perspective
The present findings support the evaluation of AS in pediatric chronic pain patients as part of a comprehensive assessment battery. The links between AS and multiple HRQOL domains suggests that treatment components aimed at reducing AS may lead to enhanced psychosocial well-being in children with chronic pain.
doi:10.1016/j.jpain.2007.05.011
PMCID: PMC2084210  PMID: 17613277
health-related quality of life; anxiety sensitivity; children; chronic pain; pain-related anxiety; functional impairment
8.  Chronic pain and pain-related disability across psychiatric disorders in a clinical adolescent sample 
BMC Psychiatry  2013;13:272.
Background
People who suffer from psychiatric disorders are burdened with a high prevalence of chronic illnesses and pain, but evidence on pain prevalence among adolescents with psychiatric disorders is scarce. The aim of this study was to investigate the frequency and location of self-reported chronic pain and pain-related disability in adolescent psychiatric patients.
Methods
This study was part of the larger Health Survey administered at the Department of Child and Adolescent Psychiatry (CAP) at St. Olav’s University Hospital, in Trondheim, Norway. All patients aged 13–18 years who visited the CAP clinic at least once between February 15, 2009 and February 15, 2011 were invited to participate. A total of 717 (43.5% of eligible/invited patients) participated; of these, 566 were diagnosed with one or more psychiatric disorders. The adolescents completed a questionnaire, which included questions about pain and pain-related disability. Clinical diagnoses were classified by a clinician according to International Statistical Classification of Diseases and Related Health Problems, 10th revision criteria.
Results
In adolescents with psychiatric disorders, 70.4% reported chronic pain, and 37.3% experienced chronic pain in three or more locations (multisite pain). Chronic musculoskeletal pain was the most prevalent type of pain (57.7%). Pain-related disability was found in 22.2% of the sample. The frequency of chronic pain and multisite pain increased with age, and girls reported a higher frequency of chronic pain, multisite pain and pain-related disability than boys did. There was an increased risk of chronic pain among adolescents with mood or anxiety disorders versus those with hyperkinetic disorders, yet this was not present after adjusting for sex. Comorbidity between hyperkinetic and mood or anxiety disorders involved an increased risk of pain-related disability.
Conclusions
In this study, seven out of 10 adolescents with psychiatric disorders reported chronic pain. These findings indicate the importance of early detection of chronic pain in adolescents with psychiatric disorders, to provide targeted treatment and reduce poor long-term outcomes.
doi:10.1186/1471-244X-13-272
PMCID: PMC3853574  PMID: 24139217
Chronic pain; Disability; Prevalence; Psychiatric disorders; Adolescents
9.  Characteristics of highly impaired children with severe chronic pain: a 5-year retrospective study on 2249 pediatric pain patients 
BMC Pediatrics  2012;12:54.
Background
Prevalence of pain as a recurrent symptom in children is known to be high, but little is known about children with high impairment from chronic pain seeking specialized treatment. The purpose of this study was the precise description of children with high impairment from chronic pain referred to the German Paediatric Pain Centre over a 5-year period.
Methods
Demographic variables, pain characteristics and psychometric measures were assessed at the first evaluation. Subgroup analysis for sex, age and pain location was conducted and multivariate logistic regression applied to identify parameters associated with extremely high impairment.
Results
The retrospective study consisted of 2249 children assessed at the first evaluation. Tension type headache (48%), migraine (43%) and functional abdominal pain (11%) were the most common diagnoses with a high rate of co-occurrence; 18% had some form of musculoskeletal pain disease. Irrespective of pain location, chronic pain disorder with somatic and psychological factors was diagnosed frequently (43%). 55% of the children suffered from more than one distinct pain diagnosis. Clinically significant depression and general anxiety scores were expressed by 24% and 19% of the patients, respectively. Girls over the age of 13 were more likely to seek tertiary treatment compared to boys. Nearly half of children suffered from daily or constant pain with a mean pain value of 6/10. Extremely high pain-related impairment, operationalized as a comprehensive measure of pain duration, frequency, intensity, pain-related school absence and disability, was associated with older age, multiple locations of pain, increased depression and prior hospital stays. 43% of the children taking analgesics had no indication for pharmacological treatment.
Conclusion
Children with chronic pain are a diagnostic and therapeutic challenge as they often have two or more different pain diagnoses, are prone to misuse of analgesics and are severely impaired. They are at increased risk for developmental stagnation. Adequate treatment and referral are essential to interrupt progression of the chronic pain process into adulthood.
doi:10.1186/1471-2431-12-54
PMCID: PMC3404028  PMID: 22591492
Children; Chronic pain; Impairment; Risk factors; Pediatric
10.  Perception of venipuncture pain in children suffering from chronic diseases 
BMC Research Notes  2014;7:735.
Background
Venipuncture pain in children results from a variety of co-factors which increase the intensity of the nociceptive stimulus. Among them, anticipatory anxiety plays an important role. Children with chronic diseases undergo invasive procedures and venipuncture more often than other children. Some healthcare professionals still believe that children who are repeatedly exposed to painful procedures, such as children with chronic diseases, gradually increase their pain tolerance and that, as a result, they have a higher pain threshold than children with no chronic diseases. The purpose of this study was to assess whether a difference exists in the perception of venipuncture pain between children with chronic diseases and children with no previous health problems nor experience of venipuncture.
Methods
A cross-sectional study was carried out using the Wong and numeric pain scales and the Observational Scale of Behavioral Distress (OSBD) for the assessment of behavioral distress. A group of children with chronic diseases and a group of children with no previous health problems nor experience of venipuncture, aged 4 to 12 years, both boys and girls, were observed during a standardized venipuncture procedure.
Results
The study included 230 children in total: 82 of them suffered from chronic diseases and had already experienced venipuncture at least once, while the remaining 148 children had no previous experience of venipuncture. The children with chronic diseases reported more pain (median pain score of 8 on the Wong or numeric scales,) and showed more signs of behavioral distress (median score of 27 on the OSBD) than non-chronic children (median pain score of 2 on the Wong/numeric scales, p = 0.00001; median OSBD score 5, p = 0.00001).
Conclusions
Our study suggests that children with chronic diseases have a lower pain threshold than children of the same sex and age who experience venipuncture for the first time.
doi:10.1186/1756-0500-7-735
PMCID: PMC4210598  PMID: 25326685
11.  The associations between psychosocial aspects and TMD-pain related aspects in children and adolescents 
Background
Temporomandibular disorders (TMD) in children and adolescents is prevalent with pain as a common component, and has a comorbidity with psychosocial problems such as stress, depression, anxiety as well as somatic complaints. Therefore, the aim of the study was to investigate if psychosocial problems in children and adolescents are associated with TMD with pain (TMD-pain) and TMD without pain (TMD-painfree) when compared to children and adolescents without TMD.
Methods
This cross-sectional study consisted of 456 randomly selected children and adolescents, enrolled from 10 boy’s- and 10 girl’s- schools in Jeddah, between 10 and 18 years of age. On the examination day, prior to the clinical examination according to Research Diagnostic Criteria for TMD Axis I and II, the participants first answered two validated questions about TMD pain, and after that the Arabic version of the Youth Self Report scale. According to their clinical examination and diagnosis the participants were divided into three groups; non-TMD group, TMD-pain group, and TMD-painfree group.
Results
The TMD-pain group presents a higher frequency of the internalizing problems anxiety, depression and somatic complaints than non-TMD group (p < 0.05). Regarding externalizing problems the only significant association found was for aggressive behavior in the TMD-pain group (p < 0.05). The TMD-pain group also shows a higher frequency of social problems than the non-TMD group. However, no such difference was found when compared to the TMD-painfree group. There was also a significant association with a higher frequency of thought problems in the TMD-pain group (p < 0.05). The children’s and adolescents’ physical activities were within border line clinical range for all three groups, whereas the social competence was within the normal range. There were no significant associations between any of the groups in this respect.
Conclusions
TMD-pain in children and adolescents does not seem to affect the social activities. However, TMD-pain seem to have a strong association to emotional, behavior and somatic functioning, with higher frequencies of anxiety, depression, somatic problems, aggressive behavior and thought problems, than children and adolescents without TMD-pain. With respect to the biopsychosocial model the present study indicates that there are significant associations to psychosocial, somatic and behavioral comorbidities and TMD-pain in children and adolescents in the Middle East region.
doi:10.1186/s10194-016-0622-0
PMCID: PMC4820412  PMID: 27044436
Temporomandibular disorders; Children; Adolescents; Psychosocial; Pain
12.  Relationship of Salivary Alpha Amylase and Cortisol to Social Anxiety in Healthy Children Undergoing Laboratory Pain Tasks 
Objective
Salivary alpha amylase (sAA) has been shown to be a sensitive and reliable marker of the autonomic nervous system (ANS) response to stress. A link between sAA, cortisol, and social/evaluative stress has been established in youth, but little is known about these relationships in response to other stressors in children, and how social anxiety might moderate these relationships. The current study explored the associations among sAA and salivary cortisol responses to laboratory pain tasks and self-reported social anxiety symptoms in a sample of healthy children.
Method
Two hundred thirty-one children (114 girls; 49.4%) with a mean age 12.68 years (SD=3.0; range 7–18) participated in the study. Participants completed self-report questionnaires prior to undergoing a series of laboratory pain tasks involving cold, pressure, and heat pain. Saliva samples were collected upon arrival to the laboratory (pre-task), following the completion of the pain tasks (post-task1), and 20 minutes after the completion of the pain tasks (post-task2).
Results
Demographic factors (age, sex, pubertal stage) did not predict either sAA or cortisol levels. However, children reporting higher levels of social anxiety demonstrated significantly higher sAA but not cortisol levels across three salivary collection times, compared to children reporting lower levels of social anxiety. Further, it does not appear that reduced state levels of anxiety before or during the tasks buffer this relationship.
Conclusion
These data highlight the possibility of identifying biomarkers of stress that are consistent across time and developmental stage. sAA appears to be a marker of stress response in children with self-reported social anxiety. There may also be a potentially unique relationship of sAA to stress in this population. In addition, sAA may reflect stable individual differences in levels of ANS arousal and may be a useful biomarker for identifying children at risk for stress.
doi:10.4172/jcalb.1000129
PMCID: PMC4267054  PMID: 25525630
Alpha amylase; Cortisol; Social anxiety; Anxiety; stress; Children; Youth; Pain
13.  Psychological therapies (remotely delivered) for the management of chronic and recurrent pain in children and adolescents 
Background
Chronic pain is common during childhood and adolescence and is associated with negative outcomes such as increased severity of pain, reduced function (e.g. missing school), and low mood (e.g. high levels of depression and anxiety). Psychological therapies, traditionally delivered face-to-face with a therapist, are efficacious at reducing pain intensity and disability. However, new and innovative technology is being used to deliver these psychological therapies remotely, meaning barriers to access to treatment such as distance and cost can be removed or reduced. Therapies delivered with technological devices, such as the Internet, computer-based programmes, smartphone applications, or via the telephone, can be used to deliver treatment to children and adolescents with chronic pain.
Objectives
To determine the efficacy of psychological therapies delivered remotely compared to waiting-list, treatment-as-usual, or active control treatments, for the management of chronic pain in children and adolescents.
Search methods
We searched four databases (CENTRAL, MEDLINE, EMBASE, and PsycINFO) from inception to June 2014 for randomised controlled trials of remotely delivered psychological interventions for children and adolescents (0 to 18 years of age) with chronic pain. We searched for chronic pain conditions including, but not exclusive to, headache, recurrent abdominal pain, musculoskeletal pain, and neuropathic pain. We also searched online trial registries for potential trials. A citation and reference search for all included studies was conducted.
Selection criteria
All included studies were randomised controlled trials that investigated the efficacy of a psychological therapy delivered remotely via the Internet, smartphone device, computer-based programme, audiotapes, or over the phone in comparison to an active, treatment-as-usual, or waiting-list control. We considered blended treatments, which used a combination of technology and face-to-face interaction. We excluded interventions solely delivered face-to-face between therapist and patient from this review. Children and adolescents (0 to 18 years of age) with a primary chronic pain condition were the target of the interventions. Each comparator arm, at each extraction point had to include 10 or more participants.
Data collection and analysis
For the analyses, we combined all psychological therapies. We split pain conditions into headache and mixed (non-headache) pain and analysed them separately. Pain, disability, depression, anxiety, and adverse events were extracted as primary outcomes. We also extracted satisfaction with treatment as a secondary outcome. We considered outcomes at two time points: first immediately following the end of treatment (known as ’post-treatment’), and second, any follow-up time point post-treatment between 3 and 12 months (known as ’follow-up’). We assessed all included studies for risk of bias.
Main results
Eight studies (N = 371) that delivered treatment remotely were identified from our search; five studies investigated children with headache conditions, one study was with children with juvenile idiopathic arthritis, and two studies included mixed samples of children with headache and mixed (i.e. recurrent abdominal pain, musculoskeletal pain) chronic pain conditions. The average age of children receiving treatment was 12.57 years.
For headache pain conditions, we found one beneficial effect of remotely delivered psychological therapy. Headache severity was reduced post-treatment (risk ratio (RR) = 2.65, 95% confidence interval (CI) 1.56 to 4.50, z = 3.62,p < 0.01, number needed to treat to benefit (NNTB) = 2.88). For mixed pain conditions, we found only one beneficial effect: psychological therapies reduced pain intensity post-treatment (standardised mean difference (SMD) = −0.61, 95% CI −0.96 to −0.25, z = 3.38, p < 0.01). No effects were found for reducing pain at follow-up in either analysis. For headache and mixed conditions, there were no beneficial effects of psychological therapies delivered remotely for disability post-treatment and a lack of data at follow-up meant no analyses could be run. Only one analysis could be conducted for depression outcomes. We found no beneficial effect of psychological therapies in reducing depression post-treatment for headache conditions. Only one study presented data in children with mixed pain conditions for depressive outcomes and no data were available for either condition at follow-up. Only one study presented anxiety data post-treatment and no studies reported follow-up data, therefore no analyses could be run. Further, there were no data available for adverse events, meaning that we are unsure whether psychological therapies are harmful to children who receive them. Satisfaction with treatment is described qualitatively.
‘Risk of bias’ assessments were low or unclear. We judged selection, detection, and reporting biases to be mostly low risk for included studies. However, judgements made on performance and attrition biases were mostly unclear.
Authors’ conclusions
Psychological therapies delivered remotely, primarily via the Internet, confer benefit in reducing the intensity or severity of pain after treatment across conditions. There is considerable uncertainty around these estimates of effect and only eight studies with 371 children contribute to the conclusions. Future studies are likely to change the conclusions reported here. All included trials used either behavioural or cognitive behavioural therapies for children with chronic pain, therefore we cannot generalise our findings to other therapies. However, satisfaction with these treatments was generally positive. Larger trials are needed to increase our confidence in all conclusions regarding the efficacy of remotely delivered psychological therapies. Implications for practice and research are discussed.
doi:10.1002/14651858.CD011118.pub2
PMCID: PMC4833498  PMID: 25803793
14.  Child Mortality Estimation: Estimating Sex Differences in Childhood Mortality since the 1970s 
PLoS Medicine  2012;9(8):e1001287.
Cheryl Sawyer uses new methods to generate estimates of sex differences in child mortality which can be used to pinpoint areas where these differences in mortality merit closer examination.
Introduction
Producing estimates of infant (under age 1 y), child (age 1–4 y), and under-five (under age 5 y) mortality rates disaggregated by sex is complicated by problems with data quality and availability. Interpretation of sex differences requires nuanced analysis: girls have a biological advantage against many causes of death that may be eroded if they are disadvantaged in access to resources. Earlier studies found that girls in some regions were not experiencing the survival advantage expected at given levels of mortality. In this paper I generate new estimates of sex differences for the 1970s to the 2000s.
Methods and Findings
Simple fitting methods were applied to male-to-female ratios of infant and under-five mortality rates from vital registration, surveys, and censuses. The sex ratio estimates were used to disaggregate published series of both-sexes mortality rates that were based on a larger number of sources. In many developing countries, I found that sex ratios of mortality have changed in the same direction as historically occurred in developed countries, but typically had a lower degree of female advantage for a given level of mortality. Regional average sex ratios weighted by numbers of births were found to be highly influenced by China and India, the only countries where both infant mortality and overall under-five mortality were estimated to be higher for girls than for boys in the 2000s. For the less developed regions (comprising Africa, Asia excluding Japan, Latin America/Caribbean, and Oceania excluding Australia and New Zealand), on average, boys' under-five mortality in the 2000s was about 2% higher than girls'. A number of countries were found to still experience higher mortality for girls than boys in the 1–4-y age group, with concentrations in southern Asia, northern Africa/western Asia, and western Africa. In the more developed regions (comprising Europe, northern America, Japan, Australia, and New Zealand), I found that the sex ratio of infant mortality peaked in the 1970s or 1980s and declined thereafter.
Conclusions
The methods developed here pinpoint regions and countries where sex differences in mortality merit closer examination to ensure that both sexes are sharing equally in access to health resources. Further study of the distribution of causes of death in different settings will aid the interpretation of differences in survival for boys and girls.
Please see later in the article for the Editors' Summary.
Editors' Summary
Background
In 2000, world leaders agreed to eradicate extreme poverty by 2015. To help track progress towards this global commitment, eight Millennium Development Goals (MDGs) were set. MDG 4, which aims to reduce child mortality, calls for a reduction in under-five mortality (the number of children who die before their fifth birthday) to a third of its 1990 level of 12 million by 2015. The under-five mortality rate is also denoted in the literature as U5MR and 5q0. Progress towards MDG 4 has been substantial, but with only three years left to reach it, efforts to strengthen child survival programs are intensifying. Reliable estimates of trends in childhood mortality are pivotal to these efforts. So, since 2004, the United Nations Inter-agency Group for Child Mortality Estimation (UN IGME) has used statistical regression models to produce estimates of trends in under-five mortality and infant mortality (death before age one year) from data about childbearing and child survival collected by vital registration systems (records of all births and deaths), household surveys, and censuses.
Why Was This Study Done?
In addition to estimates of overall childhood mortality trends, information about sex-specific childhood mortality trends is desirable to monitor progress towards MDG 4, although the interpretation of trends in the relative mortality of girls and boys is not straightforward. Newborn girls survive better than newborn boys because they are less vulnerable to birth complications and infections and have fewer inherited abnormalities. Thus, the ratio of infant mortality among boys to infant mortality among girls is greater than one, provided both sexes have equal access to food and medical care. Beyond early infancy, girls and boys are similarly vulnerable to infections, so the sex ratio of deaths in the 1–4-year age group is generally lower than that of infant mortality. Notably, as living conditions improve in developing countries, infectious diseases become less important as causes of death. Thus, in the absence of sex-specific differences in the treatment of children, the sex ratio of childhood mortality is expected be greater than one and to increase as overall under-five mortality rates in developing countries decrease. In this study, the researcher evaluated national and regional changes in the sex ratios of childhood mortality since the 1970s to investigate whether girls and boys have equal access to medical care and other resources.
What Did the Researcher Do and Find?
The researcher developed new statistical fitting methods to estimate trends in the sex ratio of mortality for infants and young children for individual countries and world regions. When considering individual countries, the researcher found that for 92 countries in less developed regions, the median sex ratio of under-five mortality increased between the 1970s and the 2000s, in line with the expected changes just described. However, the average sex ratio of under-five mortality for less developed regions, weighted according to the number of births in each country, did not increase between the 1970s and 2000s, at which time the average under-five mortality rate of boys was about 2% higher than that of girls. This discrepancy resulted from India and China—the two most populous developing countries—having sex ratios for both infant and under-five mortality that remained constant or declined over the study period and were below one in the 2000s, a result that indicates excess female mortality. In China, for example, infant mortality was found to be 12% higher for boys than for girls in the 1970s, but 24% lower for boys than for girls in the 2000s. Finally, although in the less developed regions (excluding India and China) girls went from having a slight survival disadvantage at ages 1–4 years in the 1970s, on average, to having a slight advantage in the 2000s, girls remained more likely to die than boys in this age group in several Asian and African countries.
What Do These Findings Mean?
Although the quality of the available data is likely to affect the accuracy of these findings, in most developing countries the ratio of male to female under-five mortality has increased since the 1970s, in parallel with the decrease in overall childhood mortality. Notably, however, in a number of developing countries—including several each in sub-Saharan Africa, northern Africa/western Asia, and southern Asia—girls have higher mortality than boys at ages 1–4 years, and in India and China girls have higher mortality in infancy. Thus, girls are benefitting less than boys from the overall decline in childhood mortality in India, China, and some other developing countries. Further studies are needed to determine the underlying reasons for this observation. Nevertheless, the methods developed here to estimate trends in sex-specific childhood mortality pinpoint countries and regions where greater efforts should be made to ensure that both sexes have equal access to health care and other important resources during early life.
Additional Information
Please access these websites via the online version of this summary at http://dx.doi.org/10.1371/journal.pmed.1001287.
This paper is part of a collection of papers on Child Mortality Estimation Methods published in PLOS Medicine
The United Nations Childrens Fund works for children's rights, survival, development, and protection around the world; it provides information on Millennium Development Goal 4, and its Childinfo website provides detailed statistics about child survival and health, including a description of the United Nations Inter-agency Group for Child Mortality Estimation; the 2011 UN IGME report Levels & Trends in Child Mortality is available
The World Health Organization also has information about Millennium Development Goal 4 and provides estimates of child mortality rates (some information in several languages)
Further information about the Millennium Development Goals is available
A 2011 report by the United Nations Department of Economic and Social Affairs entitled Sex Differentials in Childhood Mortality is available
doi:10.1371/journal.pmed.1001287
PMCID: PMC3429399  PMID: 22952433
15.  Relationship of child perceptions of maternal pain to children's laboratory and non-laboratory pain 
Previous research has established links between parent and child pain. Yet little is known about sex-specific parent-child pain relationships in a non-clinical population. A sample of 186 children aged 8–18 years (49% female) provided information on maternal and self bodily-pain, assessed by asking children about the presence and location of bodily pain experienced. Children also completed three laboratory pain tasks and reported on cold pressor pain intensity, pressure pain intensity and heat pain intensity. The presence of child-reported maternal pain was consistently correlated with daughters’ bodily and laboratory pain, but not with sons’ pain in bivariate analyses. Multivariate analyses controlling for child age and maternal psychological distress indicated that children of mothers with bodily pain reported more total bodily pain sites as well as greater pressure and cold pain intensity, relative to children of mothers without bodily pain. For cold pain intensity, these results differed for boys vs. girls, in that daughters reporting maternal pain evidenced significantly higher cold pain intensity compared to daughters not reporting maternal pain. No such differences were found for boys. The findings suggest that children’s perceptions of maternal pain may play a role in influencing children’s own experience of pain and that maternal pain models may affect boys and girls differently.
PMCID: PMC2642517  PMID: 18592057
pain; sex differences; social learning; children
16.  Sex differences in the relationship between maternal fear of pain and children’s conditioned pain modulation 
Journal of Pain Research  2013;6:231-238.
Background
Parental behaviors, emotions, and cognitions are known to influence children’s response to pain. However, prior work has not tested the association between maternal psychological factors and children’s responses to a conditioned pain modulation (CPM) task. CPM refers to the reduction in perceived pain intensity for a test stimulus following application of a conditioning stimulus to a remote area of the body, and is thought to reflect the descending inhibition of nociceptive signals.
Methods
The present study examined sex differences in the association between maternal anxiety about pain and children’s CPM responses in 133 healthy children aged 8–17 years. Maternal pain anxiety was assessed using the Pain Anxiety Symptoms Scale-20. In addition to the magnitude of CPM, children’s anticipatory anxiety and pain-related fear of the CPM task were measured.
Results
Sequential multiple linear regression revealed that even after controlling for child age and general maternal psychological distress, greater maternal pain anxiety was significantly related to greater CPM anticipatory anxiety and pain-related fear in girls, and to less CPM (ie, less pain inhibition) in boys.
Conclusion
The findings indicate sex-specific relationships between maternal pain anxiety and children’s responses to a CPM task over and above that accounted for by the age of the child and the mother’s general psychological distress.
doi:10.2147/JPR.S43172
PMCID: PMC3615838  PMID: 23569396
diffuse noxious inhibitory controls; pediatric pain; mother-child relationship; cold pressor; pressure pain; laboratory pain
17.  Sex differences in the relationship between maternal negative life events and children’s laboratory pain responsivity 
Objective
Prior research has demonstrated links between psychosocial factors, including negative life events (NLE) and pain in children. The present study examined sex differences in the relationship between mother-reported NLE, child NLE, mother somatization and children’s laboratory pain responses for heat, cold and pressure pain tasks. We predicted that maternal NLE would be moderately associated with girls’ pain responses, but would not be associated with boys’ pain responses.
Method
Participants were 176 non-clinical children (89 boys) aged 8–18 years (mean = 12.2, SD = 2.7) and their mothers. Mothers and children completed questionnaires assessing their perceptions of NLE experienced in the previous 12 months.
Results
Contrary to predictions, maternal NLE were related to pain responses in both boys and girls, although in opposite directions. Thus, increased maternal stress was associated with increased pain responses in girls but with decreased pain responses in boys. In addition, the impact of maternal NLE was only apparent for heat and pain tasks, indicating differential effects for various types of pain.
Conclusion
The current findings underscore the importance of family variables in understanding sex differences in children’s pain. Future research is needed to examine the mechanisms within the parent-child relationship that contribute to sex-differentiated pain outcomes, particularly under conditions of exacerbated parental stress.
doi:10.1097/DBP.0b013e3181b0ffe4
PMCID: PMC2813770  PMID: 19668092
negative life events; children’s laboratory pain; sex differences
18.  Experimental pain responses in children with chronic pain and in healthy children: How do they differ? 
BACKGROUND:
Extant research comparing laboratory pain responses of children with chronic pain with healthy controls is mixed, with some studies indicating lower pain responsivity for controls and others showing no differences. Few studies have included different pain modalities or assessment protocols.
OBJECTIVES:
To compare pain responses among 26 children (18 girls) with chronic pain and matched controls (mean age 14.8 years), to laboratory tasks involving thermal heat, pressure and cold pain. Responses to cold pain were assessed using two different protocols: an initial trial of unspecified duration and a second trial of specified duration.
METHODS:
Four trials of pressure pain and of thermal heat pain stimuli, all of unspecified duration, were administered, as well as the two cold pain trials. Heart rate and blood pressure were assessed at baseline and after completion of the pain tasks.
RESULTS:
Pain tolerance and pain intensity did not differ between children with chronic pain and controls for the unspecified trials. For the specified cold pressor trial, 92% of children with chronic pain completed the entire trial compared with only 61.5% of controls. Children with chronic pain exhibited a trend toward higher baseline and postsession heart rate and reported more anxiety and depression symptoms compared with control children.
CONCLUSIONS:
Contextual factors related to the fixed trial may have exerted a greater influence on pain tolerance in children with chronic pain relative to controls. Children with chronic pain demonstrated a tendency toward increased arousal in anticipation of and following pain induction compared with controls.
PMCID: PMC3393051  PMID: 22518373
Acute pain; Cold pressor task; Laboratory pain; Pain intensity; Pressure pain; Thermal heat pain
19.  Anxiety Sensitivity and Pain-related Anxiety in the Prediction of Fear Responding to Bodily Sensations: A Laboratory Test 
Journal of psychosomatic research  2010;70(3):258-266.
Objective
The present investigation sought to examine the simultaneous effects of anxiety sensitivity and pain-related anxiety on fear and anxious responding to a 10% carbon dioxide enriched air challenge.
Methods
Participants included 247 adults (53% women; age M = 21.91 years, SD = 8.41) recruited from the community. At the laboratory, participants were administered a structured clinical interview, completed a battery of self-report measures, and underwent a 10% carbon dioxide enriched air challenge.
Results
Both anxiety sensitivity and pain-related anxiety were significantly and uniquely predictive of post-challenge panic attacks, total post-challenge panic attack symptoms, and intensity of cognitive panic attack symptoms. Anxiety sensitivity, but not pain-related anxiety, also was predictive of post-challenge physical panic symptoms. The observed significant effects for both anxiety sensitivity and pain-related anxiety were evident above and beyond the variance accounted for by gender, age, current level of non-specific bodily pain, and negative affectivity. Neither anxiety sensitivity nor pain-related anxiety was significantly predictive of change in anxiety focused on bodily sensations or heart rate.
Conclusion
Results suggest that anxiety sensitivity and pain-related anxiety, although related to one another, may be independently important variables underlying fear reactivity to bodily sensations.
doi:10.1016/j.jpsychores.2010.07.011
PMCID: PMC3052923  PMID: 21334497
Panic; Anxiety; Anxiety Sensitivity; Pain-anxiety; Pain
20.  Alexithymia and fear of pain independently predict heat pain intensity ratings among undergraduate university students 
BACKGROUND:
Alexithymia is a disturbance in awareness and cognitive processing of affect that is associated with over-reporting of physical symptoms, including pain. The relationship between alexithymia and other psychological constructs that are often associated with pain has yet to be evaluated.
OBJECTIVES:
The present study examined the importance of alexithymia in the pain experience in relation to other integral psychological components of Turk’s diathesis-stress model of chronic pain and disability, including fear of pain, anxiety sensitivity, pain avoidance and pain catastrophizing.
METHODS:
Heat pain stimuli, using a magnitude estimation procedure, and five questionnaires (Anxiety Sensitivity Index, Fear of Pain Questionnaire III, Pain Catastrophizing Scale, avoidance subscale of the Pain Anxiety Symptoms Scale-20 and Toronto Alexithymia Scale-20) were administered to 67 undergraduate students (44 women) with a mean (± SD) age of 20.39±3.77 years.
RESULTS:
Multiple linear regression analysis revealed that sex, fear of pain and alexithymia were the only significant predictors of average heat pain intensity (F[6, 60]=5.43; R2=0.35; P=0.008), accounting for 6.8%, 20.0% and 9.6% of unique variance, respectively. Moreover, the difficulty identifying feelings and difficulty describing feelings subscales, but not the externally oriented thinking subscale of the Toronto Alexithymia Scale-20 significantly predicted average heat pain intensity.
CONCLUSIONS:
Individuals with higher levels of alexithymia or increased fear of pain reported higher average pain intensity ratings. The relationship between alexithymia and pain intensity was unrelated to other psychological constructs usually associated with pain. These findings suggest that difficulties with emotion regulation, either through reduced emotional awareness via alexithymia or heightened emotional awareness via fear of pain, may negatively impact the pain experience.
PMCID: PMC2734517  PMID: 19714270
Alexithymia; Fear of pain; Heat pain stimulation; Pain intensity; Undergraduates
21.  Anxiety Sensitivity and Fear of Pain in Pediatric Headache Patients 
Background
Recent research suggests that anxiety sensitivity (AS) may be a critical factor in the maintenance of chronic pain. Converging lines of evidence also propose a relationship between anxiety sensitivity and fear of pain that may result from interoceptive fear conditioning in interoceptively-biased individuals. While some anxiety sensitivity and fear of pain research has been done in adults, literature exploring this relationship is sparse in clinical pediatric populations.
Methods
This study investigated the hypotheses that fear of pain mediates the relationships between AS and disability as well as AS and somatization in children and adolescents with chronic headache pain. Mediation models were investigated using bootstrap regression analyses.
Results
Results indicate that the anxiety sensitivity-disability relationship is mediated by fear of pain while anxiety sensitivity seems to contribute both directly and indirectly to somatization.
Conclusion
These results provide evidence for the pivotal role of anxiety sensitivity in the pediatric chronic pain model. The findings of this study further emphasize the application of the fear-avoidance model in children, and provide new evidence for the critical role of anxiety sensitivity in a pediatric headache population.
doi:10.1002/ejp.542
PMCID: PMC4265313  PMID: 24925092
22.  Clinical Utility of Vitamin D Testing 
Executive Summary
This report from the Medical Advisory Secretariat (MAS) was intended to evaluate the clinical utility of vitamin D testing in average risk Canadians and in those with kidney disease. As a separate analysis, this report also includes a systematic literature review of the prevalence of vitamin D deficiency in these two subgroups.
This evaluation did not set out to determine the serum vitamin D thresholds that might apply to non-bone health outcomes. For bone health outcomes, no high or moderate quality evidence could be found to support a target serum level above 50 nmol/L. Similarly, no high or moderate quality evidence could be found to support vitamin D’s effects in non-bone health outcomes, other than falls.
Vitamin D
Vitamin D is a lipid soluble vitamin that acts as a hormone. It stimulates intestinal calcium absorption and is important in maintaining adequate phosphate levels for bone mineralization, bone growth, and remodelling. It’s also believed to be involved in the regulation of cell growth proliferation and apoptosis (programmed cell death), as well as modulation of the immune system and other functions. Alone or in combination with calcium, Vitamin D has also been shown to reduce the risk of fractures in elderly men (≥ 65 years), postmenopausal women, and the risk of falls in community-dwelling seniors. However, in a comprehensive systematic review, inconsistent results were found concerning the effects of vitamin D in conditions such as cancer, all-cause mortality, and cardiovascular disease. In fact, no high or moderate quality evidence could be found concerning the effects of vitamin D in such non-bone health outcomes. Given the uncertainties surrounding the effects of vitamin D in non-bone health related outcomes, it was decided that this evaluation should focus on falls and the effects of vitamin D in bone health and exclusively within average-risk individuals and patients with kidney disease.
Synthesis of vitamin D occurs naturally in the skin through exposure to ultraviolet B (UVB) radiation from sunlight, but it can also be obtained from dietary sources including fortified foods, and supplements. Foods rich in vitamin D include fatty fish, egg yolks, fish liver oil, and some types of mushrooms. Since it is usually difficult to obtain sufficient vitamin D from non-fortified foods, either due to low content or infrequent use, most vitamin D is obtained from fortified foods, exposure to sunlight, and supplements.
Clinical Need: Condition and Target Population
Vitamin D deficiency may lead to rickets in infants and osteomalacia in adults. Factors believed to be associated with vitamin D deficiency include:
darker skin pigmentation,
winter season,
living at higher latitudes,
skin coverage,
kidney disease,
malabsorption syndromes such as Crohn’s disease, cystic fibrosis, and
genetic factors.
Patients with chronic kidney disease (CKD) are at a higher risk of vitamin D deficiency due to either renal losses or decreased synthesis of 1,25-dihydroxyvitamin D.
Health Canada currently recommends that, until the daily recommended intakes (DRI) for vitamin D are updated, Canada’s Food Guide (Eating Well with Canada’s Food Guide) should be followed with respect to vitamin D intake. Issued in 2007, the Guide recommends that Canadians consume two cups (500 ml) of fortified milk or fortified soy beverages daily in order to obtain a daily intake of 200 IU. In addition, men and women over the age of 50 should take 400 IU of vitamin D supplements daily. Additional recommendations were made for breastfed infants.
A Canadian survey evaluated the median vitamin D intake derived from diet alone (excluding supplements) among 35,000 Canadians, 10,900 of which were from Ontario. Among Ontarian males ages 9 and up, the median daily dietary vitamin D intake ranged between 196 IU and 272 IU per day. Among females, it varied from 152 IU to 196 IU per day. In boys and girls ages 1 to 3, the median daily dietary vitamin D intake was 248 IU, while among those 4 to 8 years it was 224 IU.
Vitamin D Testing
Two laboratory tests for vitamin D are available, 25-hydroxy vitamin D, referred to as 25(OH)D, and 1,25-dihydroxyvitamin D. Vitamin D status is assessed by measuring the serum 25(OH)D levels, which can be assayed using radioimmunoassays, competitive protein-binding assays (CPBA), high pressure liquid chromatography (HPLC), and liquid chromatography-tandem mass spectrometry (LC-MS/MS). These may yield different results with inter-assay variation reaching up to 25% (at lower serum levels) and intra-assay variation reaching 10%.
The optimal serum concentration of vitamin D has not been established and it may change across different stages of life. Similarly, there is currently no consensus on target serum vitamin D levels. There does, however, appear to be a consensus on the definition of vitamin D deficiency at 25(OH)D < 25 nmol/l, which is based on the risk of diseases such as rickets and osteomalacia. Higher target serum levels have also been proposed based on subclinical endpoints such as parathyroid hormone (PTH). Therefore, in this report, two conservative target serum levels have been adopted, 25 nmol/L (based on the risk of rickets and osteomalacia), and 40 to 50 nmol/L (based on vitamin D’s interaction with PTH).
Ontario Context
Volume & Cost
The volume of vitamin D tests done in Ontario has been increasing over the past 5 years with a steep increase of 169,000 tests in 2007 to more than 393,400 tests in 2008. The number of tests continues to rise with the projected number of tests for 2009 exceeding 731,000. According to the Ontario Schedule of Benefits, the billing cost of each test is $51.7 for 25(OH)D (L606, 100 LMS units, $0.517/unit) and $77.6 for 1,25-dihydroxyvitamin D (L605, 150 LMS units, $0.517/unit). Province wide, the total annual cost of vitamin D testing has increased from approximately $1.7M in 2004 to over $21.0M in 2008. The projected annual cost for 2009 is approximately $38.8M.
Evidence-Based Analysis
The objective of this report is to evaluate the clinical utility of vitamin D testing in the average risk population and in those with kidney disease. As a separate analysis, the report also sought to evaluate the prevalence of vitamin D deficiency in Canada. The specific research questions addressed were thus:
What is the clinical utility of vitamin D testing in the average risk population and in subjects with kidney disease?
What is the prevalence of vitamin D deficiency in the average risk population in Canada?
What is the prevalence of vitamin D deficiency in patients with kidney disease in Canada?
Clinical utility was defined as the ability to improve bone health outcomes with the focus on the average risk population (excluding those with osteoporosis) and patients with kidney disease.
Literature Search
A literature search was performed on July 17th, 2009 using OVID MEDLINE, MEDLINE In-Process and Other Non-Indexed Citations, EMBASE, the Cumulative Index to Nursing & Allied Health Literature (CINAHL), the Cochrane Library, and the International Agency for Health Technology Assessment (INAHTA) for studies published from January 1, 1998 until July 17th, 2009. Abstracts were reviewed by a single reviewer and, for those studies meeting the eligibility criteria, full-text articles were obtained. Reference lists were also examined for any additional relevant studies not identified through the search. Articles with unknown eligibility were reviewed with a second clinical epidemiologist, then a group of epidemiologists until consensus was established. The quality of evidence was assessed as high, moderate, low or very low according to GRADE methodology.
Observational studies that evaluated the prevalence of vitamin D deficiency in Canada in the population of interest were included based on the inclusion and exclusion criteria listed below. The baseline values were used in this report in the case of interventional studies that evaluated the effect of vitamin D intake on serum levels. Studies published in grey literature were included if no studies published in the peer-reviewed literature were identified for specific outcomes or subgroups.
Considering that vitamin D status may be affected by factors such as latitude, sun exposure, food fortification, among others, the search focused on prevalence studies published in Canada. In cases where no Canadian prevalence studies were identified, the decision was made to include studies from the United States, given the similar policies in vitamin D food fortification and recommended daily intake.
Inclusion Criteria
Studies published in English
Publications that reported the prevalence of vitamin D deficiency in Canada
Studies that included subjects from the general population or with kidney disease
Studies in children or adults
Studies published between January 1998 and July 17th 2009
Exclusion Criteria
Studies that included subjects defined according to a specific disease other than kidney disease
Letters, comments, and editorials
Studies that measured the serum vitamin D levels but did not report the percentage of subjects with serum levels below a given threshold
Outcomes of Interest
Prevalence of serum vitamin D less than 25 nmol/L
Prevalence of serum vitamin D less than 40 to 50 nmol/L
Serum 25-hydroxyvitamin D was the metabolite used to assess vitamin D status. Results from adult and children studies were reported separately. Subgroup analyses according to factors that affect serum vitamin D levels (e.g., seasonal effects, skin pigmentation, and vitamin D intake) were reported if enough information was provided in the studies
Quality of Evidence
The quality of the prevalence studies was based on the method of subject recruitment and sampling, possibility of selection bias, and generalizability to the source population. The overall quality of the trials was examined according to the GRADE Working Group criteria.
Summary of Findings
Fourteen prevalence studies examining Canadian adults and children met the eligibility criteria. With the exception of one longitudinal study, the studies had a cross-sectional design. Two studies were conducted among Canadian adults with renal disease but none studied Canadian children with renal disease (though three such US studies were included). No systematic reviews or health technology assessments that evaluated the prevalence of vitamin D deficiency in Canada were identified. Two studies were published in grey literature, consisting of a Canadian survey designed to measure serum vitamin D levels and a study in infants presented as an abstract at a conference. Also included were the results of vitamin D tests performed in community laboratories in Ontario between October 2008 and September 2009 (provided by the Ontario Association of Medical Laboratories).
Different threshold levels were used in the studies, thus we reported the percentage of subjects with serum levels of between 25 and 30 nmol/L and between 37.5 and 50 nmol/L. Some studies stratified the results according to factors affecting vitamin D status and two used multivariate models to investigate the effects of these characteristics (including age, season, BMI, vitamin D intake, skin pigmentation, and season) on serum 25(OH)D levels. It’s unclear, however, if these studies were adequately powered for these subgroup analyses.
Study participants generally consisted of healthy, community-dwelling subjects and most excluded individuals with conditions or medications that alter vitamin D or bone metabolism, such as kidney or liver disease. Although the studies were conducted in different parts of Canada, fewer were performed in Northern latitudes, i.e. above 53°N, which is equivalent to the city of Edmonton.
Adults
Serum vitamin D levels of < 25 to 30 nmol/L were observed in 0% to 25.5% of the subjects included in five studies; the weighted average was 3.8% (95% CI: 3.0, 4.6). The preliminary results of the Canadian survey showed that approximately 5% of the subjects had serum levels below 29.5 nmol/L. The results of over 600,000 vitamin D tests performed in Ontarian community laboratories between October 2008 and September 2009 showed that 2.6% of adults (> 18 years) had serum levels < 25 nmol/L.
The prevalence of serum vitamin D levels below 37.5-50 nmol/L reported among studies varied widely, ranging from 8% to 73.6% with a weighted average of 22.5%. The preliminary results of the CHMS survey showed that between 10% and 25% of subjects had serum levels below 37 to 48 nmol/L. The results of the vitamin D tests performed in community laboratories showed that 10% to 25% of the individuals had serum levels between 39 and 50 nmol/L.
In an attempt to explain this inter-study variation, the study results were stratified according to factors affecting serum vitamin D levels, as summarized below. These results should be interpreted with caution as none were adjusted for other potential confounders. Adequately powered multivariate analyses would be necessary to determine the contribution of risk factors to lower serum 25(OH)D levels.
Seasonal variation
Three adult studies evaluating serum vitamin D levels in different seasons observed a trend towards a higher prevalence of serum levels < 37.5 to 50 nmol/L during the winter and spring months, specifically 21% to 39%, compared to 8% to 14% in the summer. The weighted average was 23.6% over the winter/spring months and 9.6% over summer. The difference between the seasons was not statistically significant in one study and not reported in the other two studies.
Skin Pigmentation
Four studies observed a trend toward a higher prevalence of serum vitamin D levels < 37.5 to 50 nmol/L in subjects with darker skin pigmentation compared to those with lighter skin pigmentation, with weighted averages of 46.8% among adults with darker skin colour and 15.9% among those with fairer skin.
Vitamin D intake and serum levels
Four adult studies evaluated serum vitamin D levels according to vitamin D intake and showed an overall trend toward a lower prevalence of serum levels < 37.5 to 50 nmol/L with higher levels of vitamin D intake. One study observed a dose-response relationship between higher vitamin D intake from supplements, diet (milk), and sun exposure (results not adjusted for other variables). It was observed that subjects taking 50 to 400 IU or > 400 IU of vitamin D per day had a 6% and 3% prevalence of serum vitamin D level < 40 nmol/L, respectively, versus 29% in subjects not on vitamin D supplementation. Similarly, among subjects drinking one or two glasses of milk per day, the prevalence of serum vitamin D levels < 40 nmol/L was found to be 15%, versus 6% in those who drink more than two glasses of milk per day and 21% among those who do not drink milk. On the other hand, one study observed little variation in serum vitamin D levels during winter according to milk intake, with the proportion of subjects exhibiting vitamin D levels of < 40 nmol/L being 21% among those drinking 0-2 glasses per day, 26% among those drinking > 2 glasses, and 20% among non-milk drinkers.
The overall quality of evidence for the studies conducted among adults was deemed to be low, although it was considered moderate for the subgroups of skin pigmentation and seasonal variation.
Newborn, Children and Adolescents
Five Canadian studies evaluated serum vitamin D levels in newborns, children, and adolescents. In four of these, it was found that between 0 and 36% of children exhibited deficiency across age groups with a weighted average of 6.4%. The results of over 28,000 vitamin D tests performed in children 0 to 18 years old in Ontario laboratories (Oct. 2008 to Sept. 2009) showed that 4.4% had serum levels of < 25 nmol/L.
According to two studies, 32% of infants 24 to 30 months old and 35.3% of newborns had serum vitamin D levels of < 50 nmol/L. Two studies of children 2 to 16 years old reported that 24.5% and 34% had serum vitamin D levels below 37.5 to 40 nmol/L. In both studies, older children exhibited a higher prevalence than younger children, with weighted averages 34.4% and 10.3%, respectively. The overall weighted average of the prevalence of serum vitamin D levels < 37.5 to 50 nmol/L among pediatric studies was 25.8%. The preliminary results of the Canadian survey showed that between 10% and 25% of subjects between 6 and 11 years (N= 435) had serum levels below 50 nmol/L, while for those 12 to 19 years, 25% to 50% exhibited serum vitamin D levels below 50 nmol/L.
The effects of season, skin pigmentation, and vitamin D intake were not explored in Canadian pediatric studies. A Canadian surveillance study did, however, report 104 confirmed cases1 (2.9 cases per 100,000 children) of vitamin D-deficient rickets among Canadian children age 1 to 18 between 2002 and 2004, 57 (55%) of which from Ontario. The highest incidence occurred among children living in the North, i.e., the Yukon, Northwest Territories, and Nunavut. In 92 (89%) cases, skin pigmentation was categorized as intermediate to dark, 98 (94%) had been breastfed, and 25 (24%) were offspring of immigrants to Canada. There were no cases of rickets in children receiving ≥ 400 IU VD supplementation/day.
Overall, the quality of evidence of the studies of children was considered very low.
Kidney Disease
Adults
Two studies evaluated serum vitamin D levels in Canadian adults with kidney disease. The first included 128 patients with chronic kidney disease stages 3 to 5, 38% of which had serum vitamin D levels of < 37.5 nmol/L (measured between April and July). This is higher than what was reported in Canadian studies of the general population during the summer months (i.e. between 8% and 14%). In the second, which examined 419 subjects who had received a renal transplantation (mean time since transplantation: 7.2 ± 6.4 years), the prevalence of serum vitamin D levels < 40 nmol/L was 27.3%. The authors concluded that the prevalence observed in the study population was similar to what is expected in the general population.
Children
No studies evaluating serum vitamin D levels in Canadian pediatric patients with kidney disease could be identified, although three such US studies among children with chronic kidney disease stages 1 to 5 were. The mean age varied between 10.7 and 12.5 years in two studies but was not reported in the third. Across all three studies, the prevalence of serum vitamin D levels below the range of 37.5 to 50 nmol/L varied between 21% and 39%, which is not considerably different from what was observed in studies of healthy Canadian children (24% to 35%).
Overall, the quality of evidence in adults and children with kidney disease was considered very low.
Clinical Utility of Vitamin D Testing
A high quality comprehensive systematic review published in August 2007 evaluated the association between serum vitamin D levels and different bone health outcomes in different age groups. A total of 72 studies were included. The authors observed that there was a trend towards improvement in some bone health outcomes with higher serum vitamin D levels. Nevertheless, precise thresholds for improved bone health outcomes could not be defined across age groups. Further, no new studies on the association were identified during an updated systematic review on vitamin D published in July 2009.
With regards to non-bone health outcomes, there is no high or even moderate quality evidence that supports the effectiveness of vitamin D in outcomes such as cancer, cardiovascular outcomes, and all-cause mortality. Even if there is any residual uncertainty, there is no evidence that testing vitamin D levels encourages adherence to Health Canada’s guidelines for vitamin D intake. A normal serum vitamin D threshold required to prevent non-bone health related conditions cannot be resolved until a causal effect or correlation has been demonstrated between vitamin D levels and these conditions. This is as an ongoing research issue around which there is currently too much uncertainty to base any conclusions that would support routine vitamin D testing.
For patients with chronic kidney disease (CKD), there is again no high or moderate quality evidence supporting improved outcomes through the use of calcitriol or vitamin D analogs. In the absence of such data, the authors of the guidelines for CKD patients consider it best practice to maintain serum calcium and phosphate at normal levels, while supplementation with active vitamin D should be considered if serum PTH levels are elevated. As previously stated, the authors of guidelines for CKD patients believe that there is not enough evidence to support routine vitamin D [25(OH)D] testing. According to what is stated in the guidelines, decisions regarding the commencement or discontinuation of treatment with calcitriol or vitamin D analogs should be based on serum PTH, calcium, and phosphate levels.
Limitations associated with the evidence of vitamin D testing include ambiguities in the definition of an ‘adequate threshold level’ and both inter- and intra- assay variability. The MAS considers both the lack of a consensus on the target serum vitamin D levels and assay limitations directly affect and undermine the clinical utility of testing. The evidence supporting the clinical utility of vitamin D testing is thus considered to be of very low quality.
Daily vitamin D intake, either through diet or supplementation, should follow Health Canada’s recommendations for healthy individuals of different age groups. For those with medical conditions such as renal disease, liver disease, and malabsorption syndromes, and for those taking medications that may affect vitamin D absorption/metabolism, physician guidance should be followed with respect to both vitamin D testing and supplementation.
Conclusions
Studies indicate that vitamin D, alone or in combination with calcium, may decrease the risk of fractures and falls among older adults.
There is no high or moderate quality evidence to support the effectiveness of vitamin D in other outcomes such as cancer, cardiovascular outcomes, and all-cause mortality.
Studies suggest that the prevalence of vitamin D deficiency in Canadian adults and children is relatively low (approximately 5%), and between 10% and 25% have serum levels below 40 to 50 nmol/L (based on very low to low grade evidence).
Given the limitations associated with serum vitamin D measurement, ambiguities in the definition of a ‘target serum level’, and the availability of clear guidelines on vitamin D supplementation from Health Canada, vitamin D testing is not warranted for the average risk population.
Health Canada has issued recommendations regarding the adequate daily intake of vitamin D, but current studies suggest that the mean dietary intake is below these recommendations. Accordingly, Health Canada’s guidelines and recommendations should be promoted.
Based on a moderate level of evidence, individuals with darker skin pigmentation appear to have a higher risk of low serum vitamin D levels than those with lighter skin pigmentation and therefore may need to be specially targeted with respect to optimum vitamin D intake. The cause-effect of this association is currently unclear.
Individuals with medical conditions such as renal and liver disease, osteoporosis, and malabsorption syndromes, as well as those taking medications that may affect vitamin D absorption/metabolism, should follow their physician’s guidance concerning both vitamin D testing and supplementation.
PMCID: PMC3377517  PMID: 23074397
23.  Painful Intercourse Is Significantly Associated with Evoked Pain Perception and Cognitive Aspects of Pain in Women with Pelvic Pain 
Sexual Medicine  2014;3(1):14-23.
Introduction
Evidence suggests that painful intercourse, pain-related psychosocial factors, and altered pain processing magnify the pain experience, but it is not clear how these factors are related to each other.
Aim
The aims were to (i) characterize differences between women with pelvic pain and pain-free women using a battery of pain-related psychosocial measures, clinical pain ratings, and evoked local and remote pain sensitivity; and (ii) examine the relationship between intercourse pain, clinical pain, and local and remote evoked pain sensitivity.
Methods
Women with pelvic pain lasting at least 3 months and pain-free women completed questionnaires and underwent pain sensitivity testing. Self-report measures included clinical pain intensity, pain catastrophizing, pain-related fear, pain anxiety, depression, sexual function, and self-efficacy. Pain sensitivity measures included threshold and tolerance and temporal summation of pain. Separate analyses of variance (anova) were used to test group differences in self-report and pain sensitivity measures. Correlations were calculated among dyspareunia, psychosocial factors, and evoked pain.
Main Outcome Measures
Self-reported pain and pain sensitivity measures.
Results
Twenty-eight pain-free women and 14 women with pelvic pain participated in this study. Women with pelvic pain reported greater pain intensity and greater psychosocial involvement compared with pain-free women. No differences existed between groups for thermal or pressure measures, but women with pelvic pain rated their pain with pain testing significantly higher than pain-free women. Intercourse pain was significantly associated with affective and sensory pain and pressure pain ratings at the puborectalis, vulvar vestibule, adductor longus tendons, and tibialis anterior muscle.
Conclusions
Differences in local pain ratings suggest that women with pelvic pain perceive stimuli in this region as more painful than pain-free women although the magnitude of stimuli does not differ. Alappattu MJ, George SZ, Robinson ME, Fillingim RB, Moawad N, LeBrun EW, and Bishop MD. Painful intercourse is significantly associated with evoked pain perception and cognitive aspects of pain in women with pelvic pain. Sex Med 2015;3:14–23.
doi:10.1002/sm2.52
PMCID: PMC4380910  PMID: 25844171
Chronic Pelvic Pain; Dyspareunia; Quantitative Sensory Testing
24.  Anxiety and functional disability in a large sample of children and adolescents with chronic pain 
BACKGROUND:
Anxiety is the most common psychiatric condition in children and adolescents, and is linked to significant disruptions across domains of function. Due to the avoidant nature of anxiety and pain-related disability, studying anxiety symptoms in children with chronic and recurrent pain conditions is important.
OBJECTIVES:
To examine anxiety symptoms in a large cohort of children and adolescents evaluated for complex chronic and recurrent pain conditions.
METHODS:
Through retrospective chart review, data on anxiety, pain and functional disability were collected from 655 children evaluated at a multidisciplinary pain clinic over a three-year period.
RESULTS:
Approximately 11% of children and adolescents reported clinically elevated anxiety symptoms, with elevated levels across dimensions of anxiety ranging from 14% (social anxiety, worry) to 27% (physiological). In addition, a notable 31% of the sample potentially minimized their anxiety by responding in a socially desirable manner. Anxiety was linearly associated with greater pain-related functional disability, but was not directly correlated with pain. Moderation analyses revealed that at low levels of worry, higher levels of pain were associated with greater functional disability, whereas at high levels of worry, pain no longer predicted the level of functional disability.
CONCLUSIONS:
These findings document the prevalence of anxiety in children and adolescents with chronic pain, and also extend recent studies examining the complex relationships among pain, anxiety and pain-related disability.
PMCID: PMC3393050  PMID: 22518371
Adolescents; Anxiety; Chronic pain; Functional disability; Psychosocial functioning
25.  Endovascular Radiofrequency Ablation for Varicose Veins 
Executive Summary
Objective
The objective of the MAS evidence review was to conduct a systematic review of the available evidence on the safety, effectiveness, durability and cost–effectiveness of endovascular radiofrequency ablation (RFA) for the treatment of primary symptomatic varicose veins.
Background
The Ontario Health Technology Advisory Committee (OHTAC) met on August 26th, 2010 to review the safety, effectiveness, durability, and cost-effectiveness of RFA for the treatment of primary symptomatic varicose veins based on an evidence-based review by the Medical Advisory Secretariat (MAS).
Clinical Condition
Varicose veins (VV) are tortuous, twisted, or elongated veins. This can be due to existing (inherited) valve dysfunction or decreased vein elasticity (primary venous reflux) or valve damage from prior thrombotic events (secondary venous reflux). The end result is pooling of blood in the veins, increased venous pressure and subsequent vein enlargement. As a result of high venous pressure, branch vessels balloon out leading to varicosities (varicose veins).
Symptoms typically affect the lower extremities and include (but are not limited to): aching, swelling, throbbing, night cramps, restless legs, leg fatigue, itching and burning. Left untreated, venous reflux tends to be progressive, often leading to chronic venous insufficiency (CVI). A number of complications are associated with untreated venous reflux: including superficial thrombophlebitis as well as variceal rupture and haemorrhage. CVI often results in chronic skin changes referred to as stasis dermatitis. Stasis dermatitis is comprised of a spectrum of cutaneous abnormalities including edema, hyperpigmentation, eczema, lipodermatosclerosis and stasis ulceration. Ulceration represents the disease end point for severe CVI. CVI is associated with a reduced quality of life particularly in relation to pain, physical function and mobility. In severe cases, VV with ulcers, QOL has been rated to be as bad or worse as other chronic diseases such as back pain and arthritis.
Lower limb VV is a very common disease affecting adults – estimated to be the 7th most common reason for physician referral in the US. There is a very strong familial predisposition to VV. The risk in offspring is 90% if both parents affected, 20% when neither affected and 45% (25% boys, 62% girls) if one parent affected. The prevalence of VV worldwide ranges from 5% to 15% among men and 3% to 29% among women varying by the age, gender and ethnicity of the study population, survey methods and disease definition and measurement. The annual incidence of VV estimated from the Framingham Study was reported to be 2.6% among women and 1.9% among men and did not vary within the age range (40-89 years) studied.
Approximately 1% of the adult population has a stasis ulcer of venous origin at any one time with 4% at risk. The majority of leg ulcer patients are elderly with simple superficial vein reflux. Stasis ulcers are often lengthy medical problems and can last for several years and, despite effective compression therapy and multilayer bandaging are associated with high recurrence rates. Recent trials involving surgical treatment of superficial vein reflux have resulted in healing and significantly reduced recurrence rates.
Endovascular Radiofrequency Ablation for Varicose Veins
RFA is an image-guided minimally invasive treatment alternative to surgical stripping of superficial venous reflux. RFA does not require an operating room or general anaesthesia and has been performed in an outpatient setting by a variety of medical specialties including surgeons and interventional radiologists. Rather than surgically removing the vein, RFA works by destroying or ablating the refluxing vein segment using thermal energy delivered through a radiofrequency catheter.
Prior to performing RFA, color-flow Doppler ultrasonography is used to confirm and map all areas of venous reflux to devise a safe and effective treatment plan. The RFA procedure involves the introduction of a guide wire into the target vein under ultrasound guidance followed by the insertion of an introducer sheath through which the RFA catheter is advanced. Once satisfactory positioning has been confirmed with ultrasound, a tumescent anaesthetic solution is injected into the soft tissue surrounding the target vein along its entire length. This serves to anaesthetize the vein, insulate the heat from damaging adjacent structures, including nerves and skin and compresses the vein increasing optimal contact of the vessel wall with the electrodes or expanded prongs of the RF device. The RF generator is then activated and the catheter is slowly pulled along the length of the vein. At the end of the procedure, hemostasis is then achieved by applying pressure to the vein entry point.
Adequate and proper compression stockings and bandages are applied after the procedure to reduce the risk of venous thromboembolism and to reduce postoperative bruising and tenderness. Patients are encouraged to walk immediately after the procedure. Follow-up protocols vary, with most patients returning 1 to 3 weeks later for an initial follow-up visit. At this point, the initial clinical result is assessed and occlusion of the treated vessels is confirmed with ultrasound. Patients often have a second follow-up visit 1 to 3 months following RFA at which time clinical evaluation and ultrasound are repeated. If required, additional procedures such as phlebectomy or sclerotherapy may be performed during the RFA procedure or at any follow-up visits.
Regulatory Status
The Closure System® radiofrequency generator for endovascular thermal ablation of varicose veins was approved by Health Canada as a class 3 device in March 2005, registered under medical device license 67865. The RFA intravascular catheter was approved by Health Canada in November 2007 for the ClosureFast catheter, registered under medical device license 16574. The Closure System® also has regulatory approvals in Australia, Europe (CE Mark) and the United States (FDA clearance). In Ontario, RFA is not an insured service and is currently being introduced in private clinics.
Methods
Literature Search
The MAS evidence–based review was performed to support public financing decisions. The literature search was performed on March 9th, 2010 using standard bibliographic databases for studies published up until March, 2010.
Inclusion Criteria
English language full-reports and human studies Original reports with defined study methodologyReports including standardized measurements on outcome events such as technical success, safety, effectiveness, durability, quality of life or patient satisfaction Reports involving RFA for varicose veins (great or small saphenous veins)Randomized controlled trials (RCTs), systematic reviews and meta-analysesCohort and controlled clinical studies involving ≥ 1 month ultrasound imaging follow-up
Exclusion Criteria
Non systematic reviews, letters, comments and editorials Reports not involving outcome events such as safety, effectiveness, durability, or patient satisfaction following an intervention with RFAReports not involving interventions with RFA for varicose veinsPilot studies or studies with small samples (< 50 subjects)
Summary of Findings
The MAS evidence search on the safety and effectiveness of endovascular RFA ablation of VV identified the following evidence: three HTAs, nine systematic reviews, eight randomized controlled trials (five comparing RFA to surgery and three comparing RFA to ELT), five controlled clinical trials and fourteen cohort case series (four were multicenter registry studies).
The majority (12⁄14) of the cohort studies (3,664) evaluating RFA for VV involved treatment with first generation RFA catheters and the great saphenous vein (GSV) was the target vessel in all studies. Major adverse events were uncommonly reported and the overall pooled major adverse event rate extracted from the cohort studies was 2.9% (105⁄3,664). Imaging defined treatment effectiveness of vein closure rates were variable ranging from 68% to 96% at post-operative follow-up. Vein ablation rate at 6-month follow-up was reported in four studies with rates close to 90%. Only one study reported vein closure rates at 2 years but only for a minority of the eligible cases. The two studies reporting on RFA ablation with the more efficient second generation catheters involved better follow-up and reported higher ablation rates close to 100% at 6-month follow-up with no major adverse events. A large prospective registry trial that recruited over 1,000 patients at thirty-four largely European centers reported on treatment success in six overlapping reports on selected patient subgroups at various follow-up points up to 5 year. However, the follow-up for eligible recruited patients at all time points was low resulting in inadequate estimates of longer term treatment efficacy.
The overall level of evidence of randomized trials comparing RFA with surgical ligation and vein stripping (n = 5) was graded as low to moderate. In all trials RFA ablation was performed with first generation catheters in the setting of the operating theatre under general anaesthesia, usually without tumescent anaesthesia. Procedure times were significantly longer after RFA than surgery. Recovery after treatment was significantly quicker after RFA both with return to usual activity and return to work with on average a one week less of work loss. Major adverse events occurring after surgery were higher [(1.8% (n=4) vs. 0.4% (n = 1) than after RFA but not significantly. Treatment effectiveness measured by imaging defined vein absence or vein closure was comparable in the two treatment groups. Significant improvements in vein symptoms and quality of life over baseline were reported for both treatment groups. Improvements in these outcomes were significantly greater in the RFA group than the surgery group in the peri-operative period but not in later follow-up. Follow-up in these trials was inadequate to evaluate longer term recurrence for either treatment. Patient satisfaction was reported to be high for both treatments but was higher for RFA.
The studies comparing endovascular treatment approaches for VV (RFA and ELT) were more limited. Three RCT studies compared RFA (two with the second generation catheter) with ELT but mainly focused on peri-procedural outcomes such as pain, complications and recovery. Vein ablation rates were not evaluated in the trials, except for one small trial involving bilateral VV. Pain responses in patients undergoing ablation were extremely variable and up to 2 weeks, mean pain levels were significantly less with RFA than ELT ablation but differences were not significant at one month. Recovery, evaluated as return to usual activity or return to work, however, was similar in the treatment groups. Vein symptom and QOL improvements were improved in both groups but were significantly better in the RFA group than the ELT group at 2 weeks, but not at one month. Vein ablation rates were evaluated in several controlled clinical studies comparing the treatments between centers or within centers between individuals or over time. Comparisons in these studies were inconsistent with vein ablation rates for RFA reported to be similar to, higher than and lower than those with ELT.
Economic Analysis
RFA and surgical vein stripping, the main comparator reimbursed by the public system, are comparable in clinical benefits. Hence a cost-analysis was conducted to identify the differences in resources and costs between both procedures and a budgetary impact analysis (BIA) was conducted to project costs over a 5- year period in the province of Ontario. The target population of this economic analysis was patients with symptomatic varicose veins and the primary analytic perspective was that of the Ministry of Health and Long-Term Care.
The average case cost (based on Ontario hospital costs and medical resources) for surgical vein stripping was estimated to be $1,799. In order to calculate a procedural cost for RFA it was assumed that the hospital cost and physician labour fees, excluding anaesthesia and surgical assistance, were the same as vein stripping surgery. The manufacturer also provided details on the generator with a capital cost of $27,500 and a lifespan of 5 years and the disposables (catheter, sheath, guidewire) with a cost of $673 per case. The average case cost for RFA was therefore estimated to be $1,356. One-way sensitivity analysis was also conducted with hospital cost of RFA varied to 60% that of vein stripping surgery (average cost per case = $627.08) to calculate an impact to the province.
Historical volumes of vein stripping surgeries in Ontario were used to project surgeries in a linear fashion up to five years into the future. Volumes for RFA and ELT were calculated based on share capture from the surgery market based on discussion with clinical expert opinion and existing private data based on discussion with the manufacturer. RFA is expected to compete with ELT and capture some of the market. If ELT is reimbursed by the public sector then numbers will continue to increase from previous private data and share capture from the conventional surgical treatment market. Therefore, RFA cases will also increase since it will be capturing a share of the ELT market. A budget impact to the province was then calculated by multiplying volumes by the cost of the procedure.
RFA is comparable in clinical benefits to vein stripping surgery. It has the extra upfront cost of the generator and cost per case for disposables but does not require an operating theater, anaesthetist or surgical assistant fees. The impact to the province is expected to be 5 M by Year 5 with the introduction of new ELT and RFA image guided endovascular technologies and existing surgery for varicose veins.
Conclusion
The conclusions on the comparative outcomes between endovascular RFA and surgical ligation and saphenous vein stripping and between endovascular RFA and laser ablation for VV treatment are summarized in the table below (ES Table 1).
Outcome comparisons of RFA vs. surgery and RFA vs ELT for varicose veins
ELT refers to endovascular laser ablation; RFA, radiofrequency ablation
The outcomes of the evidence-based review on these treatments for VV based on different perspectives are summarized below:
RFA First versus Second Generation Catheters and Segmental Ablation
Ablation with second generation catheters and segmental ablation offered technical advantages with improved ease and significant decreases in procedure time. RFA ablation with second generation catheters is also no longer restricted to smaller (< 12 mm diameter) saphenous veins. The safety profile with the new device and method of energy delivery is as good as or improved over the first generation device. No major adverse events were reported in two multicenter prospective cohort studies in 6 month follow-up with over 500 patients. Post-operative complications such as bruising and pain were significantly less with RFA ablation with second generation catheters than ELT in two RCT trials.RFA treatment with second generation catheters has ablation rates that are higher than with first generation catheters and are more comparable with the consistently high rates of ELT.
Endovascular RFA versus Surgery
RFA has a quicker recovery attributable to decreased pain and lower minor complications.RFA, in the short term was comparable to surgery in treatment effectiveness as assessed by imaging defined anatomic outcomes such as vein closure, flow or reflux. Other treatment outcomes such as symptomatic relief and HRQOL were significantly improved in both groups and between group differences in the early peri-operative period were likely influenced by pain experiences. Longer term follow-up was inadequate to evaluate recurrence after either treatment.Patient satisfaction was high after both treatments but was higher for RFA than surgery.
Endovascular RFA versus ELT
RFA has significantly less post-operative pain than ELT but differences were not significant when pain was adjusted for analgesic use and pain differences between groups did not persist at 1 month follow-up.Treatment effectiveness, measured as symptom relief and QOL improvement were similar between the endovascular treatments in the short term (within 1 month) Treatment effectiveness measured as imaging defined vein ablation was not measured in any RCT trials (only for bilateral VV disease) and results were inconsistently reported in observational trials.Longer term follow-up was not available to assess recurrence after either treatment.
System Outcomes – RFA Replacing Surgery or Competing with ELT
RFA may offer system advantages in that the treatment can be offered by several medical specialties in outpatient settings and because it does not require an operating theatre or general anaesthesia. The treatment may result in decanting of patients from OR with decreased pre-surgical investigations, demand on anaesthetists’ time, hospital stay and wait time for VV treatment. It may also provide more reliable outpatient scheduling. Procedure costs may be less for endovascular approaches than surgery but the budget impact may be greater with insurance of RFA because of the transfer of cases from the private market to the public payer system.Competition between RFA and ELT endovascular approaches is likely to continue to stimulate innovation and technical changes to advance patient care and result in competitive pricing.
PMCID: PMC3377553  PMID: 23074413

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