Search tips
Search criteria

Results 1-25 (151)

Clipboard (0)

Select a Filter Below

more »
Year of Publication
more »
1.  The Relationship between Intramuscular Adipose Tissue, Functional Mobility, and Strength in Postmenopausal Women with and without Type 2 Diabetes 
Journal of Aging Research  2015;2015:872726.
Objectives. To determine (1) whether intramuscular adipose tissue (IntraMAT) differs between women with and without type 2 diabetes and (2) the association between IntraMAT and mobility and strength. Methods. 59 women ≥ 65 years with and without type 2 diabetes were included. A 1-Tesla MRI was used to acquire images of the leg. Timed-up-and-go (TUG) and grip strength were measured. Regression was used to determine associations between the following: (1) type 2 diabetes and IntraMAT (covariates: age, ethnicity, BMI, waist : hip ratio, and energy expenditure), (2) IntraMAT and TUG (covariates: diabetes, age, BMI, and energy expenditure), and (3) IntraMAT and grip strength (covariates: diabetes, age, height, and lean mass). Results. Women with diabetes had more IntraMAT. After adjustment, IntraMAT was similar between groups (diabetes mean [SD] = 13.2 [1.4]%, controls 11.8 [1.3]%, P = 0.515). IntraMAT was related to TUG and grip strength, but the relationships became nonsignificant after adjustment for covariates (difference/percent IntraMAT [95% CI]: TUG = 0.041 seconds [−0.079–0.161], P = 0.498, grip strength = −0.144 kg [−0.335–0.066], P = 0.175). Conclusions. IntraMAT alone may not be a clinically important predictor of functional mobility and strength; however, whether losses in functional mobility and strength are promoted by IntraMAT accumulation should be explored.
PMCID: PMC4322662
2.  Mobile phone text messaging interventions for HIV and other chronic diseases: an overview of systematic reviews and framework for evidence transfer 
Strong international commitment and the widespread use of antiretroviral therapy have led to higher longevity for people living with human immune deficiency virus (HIV). Text messaging interventions have been shown to improve health outcomes in people living with HIV. The objectives of this overview were to: map the state of the evidence of text messaging interventions, identify knowledge gaps, and develop a framework for the transfer of evidence to other chronic diseases.
We conducted a systematic review of systematic reviews on text messaging interventions to improve health or health related outcomes. We conducted a comprehensive search of PubMed, EMBASE (Exerpta Medica Database), CINAHL (Cumulative Index to Nursing and Allied Health Literature), PsycINFO, Web of Science (WoS) and the Cochrane Library on the 17th April 2014. Screening, data extraction and assessment of methodological quality were done in duplicate. Our findings were used to develop a conceptual framework for transfer.
Our search identified 135 potential systematic reviews of which nine were included, reporting on 37 source studies, conducted in 19 different countries. Seven of nine (77.7%) of these reviews were high quality. There was some evidence for text messaging as a tool to improve adherence to antiretroviral therapy. Text messages also improved attendance at appointments and behaviour change outcomes. The findings were inconclusive for self-management of illness, treatment of tuberculosis and communicating results of medical investigations. The geographical distribution of text messaging research was limited to specific regions of the world. Prominent knowledge gaps included the absence of data on long term outcomes, patient satisfaction, and economic evaluations. The included reviews also identified methodological limitations in many of the primary studies.
Global evidence supports the use of text messaging as a tool to improve adherence to medication and attendance at scheduled appointments. Given the similarities between HIV and other chronic diseases (long-term medications, life-long care, strong link to behaviour and the need for home-based support) evidence from HIV may be transferred to these diseases using our proposed framework by integration of HIV and chronic disease services or direct transfer.
PMCID: PMC4308847  PMID: 25609559
Text message; HIV chronic disease; Evidence transfer; Overview
3.  Management of chronic neuropathic pain: a protocol for a multiple treatment comparison meta-analysis of randomised controlled trials 
BMJ Open  2014;4(11):e006112.
Chronic neuropathic pain is associated with reduced health-related quality of life and substantial socioeconomic costs. Current research addressing management of chronic neuropathic pain is limited. No review has evaluated all interventional studies for chronic neuropathic pain, which limits attempts to make inferences regarding the relative effectiveness of treatments.
Methods and analysis
We will conduct a systematic review of all randomised controlled trials evaluating therapies for chronic neuropathic pain. We will identify eligible trials, in any language, by a systematic search of CINAHL, EMBASE, MEDLINE, AMED, HealthSTAR, DARE, PsychINFO and the Cochrane Central Registry of Controlled Trials. Eligible trials will be: (1) enrol patients presenting with chronic neuropathic pain, and (2) randomise patients to alternative interventions (pharmacological or non-pharmacological) or an intervention and a control arm. Pairs of reviewers will, independently and in duplicate, screen titles and abstracts of identified citations, review the full texts of potentially eligible trials and extract information from eligible trials. We will use a modified Cochrane instrument to evaluate risk of bias of eligible studies, recommendations from the Initiative on Methods, Measurement, and Pain Assessment in Clinical Trials (IMMPACT) to inform the outcomes we will collect, and the Grading of Recommendations Assessment, Development and Evaluation (GRADE) system to evaluate our confidence in treatment effects. When possible, we will conduct: (1) in direct comparisons, a random-effects meta-analysis to establish the effect of reported therapies on patient-important outcomes; and (2) a multiple treatment comparison meta-analysis within a Bayesian framework to assess the relative effects of treatments. We will define a priori hypotheses to explain heterogeneity between studies, and conduct meta-regression and subgroup analyses consistent with the current best practices.
Ethics and Dissemination
We do not require ethics approval for our proposed review. We will disseminate our findings through peer-reviewed publications and conference presentations.
Trial registration number
PROSPERO (CRD42014009212).
PMCID: PMC4244486  PMID: 25412864
4.  Evaluation of clinical and inflammatory profile in opioid addiction patients with comorbid pain: results from a multicenter investigation 
Chronic pain is the most commonly reported comorbidity among patients with opioid addiction receiving methadone maintenance treatment (MMT), with an estimated prevalence ranging between 30% and 55%. Evidence suggests that patients with comorbid pain are at high risk for poor treatment response, including continued illicit substance use. Due to the important relationship between the presence of pain and illicit substance abuse within the MMT setting, it is imperative that we target our efforts toward understanding the characteristics of this patient population.
The primary objective of this study was to explore the clinical and inflammatory profile of MMT patients reporting comorbid pain. This multicenter study enrolled patients (n=235) on MMT for the treatment of opioid dependence. Clinical history and blood and urine data were collected. Blood samples were obtained for estimating the serum levels of inflammatory markers (tumor necrosis factor [TNF]-α, interleukin-1 receptor antagonist [IL-1ra], IL-6, IL-8, IL-10, interferon [IFN]-γ and chemokine (C–C motif) ligand 2 [CCL2]). The study objectives were addressed using a descriptive statistical summary and a multivariable logistic regression model constructed in STATA version 12.
Among the participants eligible for inclusion (n=235), serum IFN-γ level and substance abuse behavior proved to be important delineating characteristics for the detection of comorbid pain. Analysis of inflammatory profile showed IFN-γ to be significantly elevated among patients reporting comorbid pain (odds ratio [OR]: 2.02; 95% confidence interval [CI]: 1.17, 3.50; P=0.01). Patients reporting comorbid pain were also found to have an increase in positive opioid urine screens (OR: 1.02; 95% CI: 1.00, 1.03; P=0.01), indicating an increase in illicit opioid consumption.
MMT patients with comorbid pain were shown to have elevated IFN-γ and higher rates of continued opioid abuse. The ability to objectively distinguish between patients with comorbid pain may help to both improve the prediction of poor responders to MMT as well as identify treatment approaches such as anti-inflammatory medications as safe alternatives for MMT patients with comorbid pain.
PMCID: PMC4242695  PMID: 25429222
methadone maintenance treatment; inflammatory markers; TNF-α; IFN-γ; interleukins; CCL2; Brief Pain Inventory; opioid dependence
5.  Continuous venovenous hemofiltration versus continuous venovenous hemodiafiltration in critically ill patients: A retrospective cohort study from a Canadian tertiary centre 
Critically ill patients who develop acute kidney injury are at an increased risk for death. Several trials have compared therapeutic methods and have reported superior survival benefits for some. Although there is variation in practice worldwide, it is unknown whether the methods investigated in this particular study differ with regard to patient outcomes.
Studies comparing continuous renal replacement therapy modalities are lacking. Theoretically, continuous venovenous hemofiltration (CVVH) could be more effective than continuous venovenous hemodiafiltration (CVVHDF), and may be associated with fewer complications; however, there are no published data to support this hypothesis.
To examine the effect of CVVH on mortality and other clinically important outcomes compared with CVVHDF in the intensive care unit (ICU) setting.
Using a log of all continuous renal replacement therapy performed at a Canadian tertiary centre between 2007 and 2010, the records of patients meeting the inclusion criteria of being admitted to the ICU, and receiving either CVVH or CVVHDF for management of acute renal failure, were reviewed. The information retrieved included demographic data, death events, and hospital and ICU length of stay.
Data from 153 patients were included in the present study. Hospital and 30-day mortality were similar in the CVVH and CVVHDF groups (OR 0.85 [95% CI 0.38 to 1.89]; P=0.69 and OR 1.35 [95% CI 0.62 to 2.95]; P=0.45, respectively). There was no difference in hospital length of stay (mean difference −34.14 [95% CI −72.92 to 4.65]; P=0.08).
The present retrospective review suggests that the use of CVVH does not reduce mortality or hospital length of stay when compared with CVVHDF. Future randomized trials should control for different patient populations and continue to evaluate the removal of small molecules such as hormones.
PMCID: PMC4128463  PMID: 24712012
Acute renal failure; Cohort study; Continuous renal replacement therapy; Critically ill patients
6.  Treatment crossovers in time-to-event non-inferiority randomised trials of radiotherapy in patients with breast cancer 
BMJ Open  2014;4(10):e006531.
In non-inferiority trials of radiotherapy in patients with early stage breast cancer, it is inevitable that some patients will cross over from the experimental arm to the standard arm prior to initiation of any treatment due to complexities in treatment planning or subject preference. Although the intention-to-treat (ITT) analysis is the preferred approach for superiority trials, its role in non-inferiority trials is still under debate. This has led to the use of alternative approaches such as the per-protocol (PP) analysis or the as-treated (AT) analysis, despite the inherent biases of such approaches.
Using simulations, we investigate the effect of 2%, 5% and 10% random and non-random crossovers prior to radiotherapy initiation on the ITT, PP, AT and the combination of ITT and PP analyses with respect to type I error in trials with time-to-event outcomes. We also evaluate bias and SE of the estimates from the ITT, PP and AT approaches.
The AT approach had the best performance in terms of type I error, but was anticonservative as non-random crossover increased. The ITT and PP approaches were anticonservative under all percentages of random and non-random crossover. Similarly, lowest bias was seen with the AT approach; however, bias increased as the percentage of non-random crossover increased. The ITT and PP had poor performance in terms of bias as crossovers increased.
If minimal crossovers were to occur, we have shown that the AT approach has the lowest type I error rates and smallest opportunity for bias. Results of trials with a high number of crossovers should be interpreted with caution, especially when crossover is non-random. Attempts to prevent crossovers should be maximised.
PMCID: PMC4212183  PMID: 25344487
7.  Patients’ values and preferences of the expected efficacy of hip arthroscopy for osteoarthritis: a protocol for a multinational structured interview-based study combined with a randomised survey on the optimal amount of information to elicit preferences 
BMJ Open  2014;4(10):e005536.
Symptomatic hip osteoarthritis (OA) is a disabling condition with up to a 25% cumulative lifetime risk. Total hip arthroplasty (THA) is effective in relieving patients’ symptoms and improving function. It is, however, associated with substantial risk of complications, pain and major functional limitation before patients can return to full function. In contrast, hip arthroscopy (HA) is less invasive and can postpone THA. However, there is no evidence regarding the delay in the need for THA that patients would find acceptable to undergoing HA. Knowing patients’ values and preferences (VP) on this expected delay is critical when making recommendations regarding the advisability of HA. Furthermore, little is known on the optimal amount of information regarding interventions and outcomes needed to present in order to optimally elicit patients’ VP.
Methods and analysis
We will perform a multinational, structured interview-based survey of preference in delay time for THA among patients with non-advanced OA who failed to respond to conservative therapy. We will combine these interviews with a randomised trial addressing the optimal amount of information regarding the interventions and outcomes required to elicit preferences. Eligible patients will be randomly assigned (1 : 1) to either a short or a long format of health scenarios of THA and HA. We will determine each patient's VP using a trade-off and anticipated regret exercises. Our primary outcomes for the combined surveys will be: (1) the minimal delay time in the need for THA surgery that patients would find acceptable to undertaking HA, (2) patients’ satisfaction with the amount of information provided in the health scenarios used to elicit their VPs.
Ethics and dissemination
The protocol has been approved by the Hamilton Integrated Research Ethics Board (HIREB13-506). We will disseminate our study findings through peer-reviewed publications and conference presentations, and make them available to guideline makers issuing recommendations addressing HA and THA.
PMCID: PMC4202002  PMID: 25326208
Patients' values and preference; Total Hip Arthroplasty; Hip Arthroscopy; Patient Written Information; Decision Making
8.  Evaluating the test re-test reliability and inter-subject variability of health care provider manual fluid resuscitation performance 
BMC Research Notes  2014;7(1):724.
Health Care Providers (HCPs) report that manual techniques of intravascular fluid resuscitation are commonly used during pediatric shock management. The optimal pediatric fluid resuscitation technique is currently unknown. We sought to determine HCP test-retest reliability (repeatability) and inter-subject variability of fluid resuscitation performance outcomes to inform the design of future studies.
Fifteen consenting HCPs from McMaster Children’s Hospital, in Hamilton, Canada participated in this single-arm interventional trial. Participants were oriented to a non-clinical model representing a 15 kg toddler, which incorporated a 22-gauge IV catheter. Following a standardization procedure, participants administered 600 mL (40 mL/kg) of saline to the simulated child under emergency conditions using prefilled 60-mL syringes. Each participant completed 5 testing trials. All testing was video recorded, with fluid administration time outcome data (in seconds) extracted from trial videos by two blinded outcome assessors. Data describing catheter dislodgement events, volume of saline effectively delivered, and participant demographics were also collected. The primary outcome of fluid administration time test-retest reliability was analyzed by one-way analysis of variance (ANOVA) and intra-class correlation (ICC), with good reliability defined as ICC > 0.70.
Differences in HCP fluid administration times are attributable to inter-subject variability rather than intra-subject variability based on one-way ANOVA analysis, F (14,60) = 43.125; p < 0.001. Test-retest reliability of subjects was excellent with ICC = 0.97 (95% CI: 0.95-0.99); p < 0.001.
Findings demonstrate excellent test-retest reliability of HCP fluid resuscitation performance in a setting involving a non-clinical model. Investigators can justify a single evaluation of HCP performance in future studies.
Electronic supplementary material
The online version of this article (doi:10.1186/1756-0500-7-724) contains supplementary material, which is available to authorized users.
PMCID: PMC4210565  PMID: 25315062
Research methods; Resuscitation; Shock; Fluid therapy; Pediatrics
9.  Factors associated with development of gastrointestinal problems in patients with scleroderma: a protocol for a systematic review 
Systematic Reviews  2014;3:115.
Scleroderma affects the gastrointestinal (GI) tract in 90% of all cases. Malnutrition, diarrhea, and constipation are some GI complications that can stem from scleroderma, and they contribute considerably to impairment in quality of life. Reports of haphazard clusters of high prevalence suggest that environmental exposure is a risk factor for scleroderma. However, it is largely uncertain whether the GI involvement secondary to scleroderma is influenced by these environmental factors. This study will review the association between GI involvement (unintentional weight loss, choking, early satiety, etc.) and environmental exposure in patients with scleroderma.
Any available observational studies that report GI problems in patients with scleroderma along with the associated risk factors will be selected. We will search CINAHL, EMBASE, LILACS, MEDLINE, and Web of Science for relevant articles written in English from June 1884 to May 2014. Identified articles will be screened in duplicate, and full text for selected articles will be retrieved. Data extraction will be done in duplicate on sociodemographic characteristics of participants, diagnosis of scleroderma, diagnosis of risk of GI problem, risk factors reported, etc. Discrepancies will be resolved by consensus or by consulting a third author. We will assess the participants, methods, and intervention effects of included studies for heterogeneity. Any identified clinical or statistical heterogeneity will be explored visually or using the chi-square test. Data will be pooled statistically using the DerSimmonian and Laird random effects method if we have a measure of relative risk and its precision. Our findings will be reported according to the Meta-Analyses and Systematic Review of Observational Studies (MOOSE) guideline.
Our findings may help patients with scleroderma and health care professionals in preventing GI morbidity. Knowing that the cost of care for patients with scleroderma increases with more organ involvement, study findings can inform policy developers to identify ways to curb health care costs.
Systematic review registration
PROSPERO: CRD42014010707
PMCID: PMC4201836  PMID: 25312976
Systematic review; Scleroderma; Gastrointestinal; Risk factor
10.  Accounting for center in the Early External Cephalic Version trials: an empirical comparison of statistical methods to adjust for center in a multicenter trial with binary outcomes 
Trials  2014;15(1):377.
Clustering of outcomes at centers involved in multicenter trials is a type of center effect. The Consolidated Standards of Reporting Trials Statement recommends that multicenter randomized controlled trials (RCTs) should account for center effects in their analysis, however most do not. The Early External Cephalic Version (EECV) trials published in 2003 and 2011 stratified by center at randomization, but did not account for center in the analyses, and due to the nature of the intervention and number of centers, may have been prone to center effects. Using data from the EECV trials, we undertook an empirical study to compare various statistical approaches to account for center effect while estimating the impact of external cephalic version timing (early or delayed) on the outcomes of cesarean section, preterm birth, and non-cephalic presentation at the time of birth.
The data from the EECV pilot trial and the EECV2 trial were merged into one dataset. Fisher’s exact method was used to test the overall effect of external cephalic version timing unadjusted for center effects. Seven statistical models that accounted for center effects were applied to the data. The models included: i) the Mantel-Haenszel test, ii) logistic regression with fixed center effect and fixed treatment effect, iii) center-size weighted and iv) un-weighted logistic regression with fixed center effect and fixed treatment-by-center interaction, iv) logistic regression with random center effect and fixed treatment effect, v) logistic regression with random center effect and random treatment-by-center interaction, and vi) generalized estimating equations.
For each of the three outcomes of interest approaches to account for center effect did not alter the overall findings of the trial. The results were similar for the majority of the methods used to adjust for center, illustrating the robustness of the findings.
Despite literature that suggests center effect can change the estimate of effect in multicenter trials, this empirical study does not show a difference in the outcomes of the EECV trials when accounting for center effect.
Trial registration
The EECV2 trial was registered on 30 July 30 2005 with Current Controlled Trials: ISRCTN%2056498577.
PMCID: PMC4192344  PMID: 25257928
Randomized controlled trials; Center effect; Multicenter trials; Trial design; Trial analysis; Random effect; Mixed-effects; Generalized estimating equations; Generalized linear mixed model
11.  A framework for community ownership of a text messaging programme to improve adherence to antiretroviral therapy and client-provider communication: a mixed methods study 
Mobile phone text messaging has been shown to improve adherence to antiretroviral therapy and to improve communication between patients and health care workers. It is unclear which strategies are most appropriate for scaling up text messaging programmes. We sought to investigate acceptability and readiness for ownership (community members designing, sending and receiving text messages) of a text message programme among a community of clients living with human immunodeficiency virus (HIV) in Yaoundé, Cameroon and to develop a framework for implementation.
We used the mixed-methods sequential exploratory design. In the qualitative strand we conducted 7 focus group discussions (57 participants) to elicit themes related to acceptability and readiness. In the quantitative strand we explored the generalizability of these themes in a survey of 420 clients. Qualitative and quantitative data were merged to generate meta-inferences.
Both qualitative and quantitative strands showed high levels of acceptability and readiness despite low rates of participation in other community-led projects. In the qualitative strand, compared to the quantitative strand, more potential service users were willing to pay for a text messaging service, preferred participation of health personnel in managing the project and preferred that the project be based in the hospital rather than in the community. Some of the limitations identified to implementing a community-owned project were lack of management skills in the community, financial, technical and literacy challenges. Participants who were willing to pay were more likely to find the project acceptable and expressed positive feelings about community readiness to own a text messaging project.
Community ownership of a text messaging programme is acceptable to the community of clients at the Yaoundé Central Hospital. Our framework for implementation includes components for community members who take on roles as services users (demonstrating clear benefits, allowing a trial period and ensuring high levels of confidentiality) or service providers (training in project management and securing sustainable funding). Such a project can be evaluated using participation rate, clinical outcomes, satisfaction with the service, cost and feedback from users.
Electronic supplementary material
The online version of this article (doi:10.1186/1472-6963-14-441) contains supplementary material, which is available to authorized users.
PMCID: PMC4263054  PMID: 25258249
Text messaging; Community ownership; HIV; Mixed methods; Cameroon
12.  The effectiveness of opioid substitution treatments for patients with opioid dependence: a systematic review and multiple treatment comparison protocol 
Systematic Reviews  2014;3:105.
Opioids are psychoactive analgesic drugs prescribed for pain relief and palliative care. Due to their addictive potential, effort and vigilance in controlling prescriptions is needed to avoid misuse and dependence. Despite the effort, the prevalence of opioid use disorder continues to rise. Opioid substitution therapies are commonly used to treat opioid dependence; however, there is minimal consensus as to which therapy is most effective. Available treatments include methadone, heroin, buprenorphine, as well as naltrexone. This systematic review aims to assess and compare the effect of all available opioid substitution therapies on the treatment of opioid dependence.
The authors will search Medline, EMBASE, PubMed, PsycINFO, Web of Science, Cochrane Library, Cochrane Clinical Trials Registry, World Health Organization International Clinical Trials Registry Platform Search Portal, and the National Institutes for Health Clinical Trials Registry. The title, abstract, and full-text screening will be completed in duplicate. When appropriate, multiple treatment comparison Bayesian meta-analytic methods will be performed to deduce summary statistics estimating the effectiveness of all opioid substitution therapies in terms of retention and response to treatment (as measured through continued opioid abuse).
Using evidence gained from this systematic review, we anticipate disseminating an objective review of the current available literature on the effectiveness of all opioid substitution therapies for the treatment of opioid use disorder. The results of this systematic review are imperative to the further enhancement of clinical practice in addiction medicine.
Systematic review registration
PROSPERO CRD42013006507.
PMCID: PMC4171401  PMID: 25239213
Opioid substitution therapies; Opioid dependence; Methadone; Buprenorphine/naloxone; Naltrexone; Heroin; Systematic review; Network meta-analysis
13.  CIHR canadian HIV trials network HIV workshop: ethical research through community participation and strengthening scientific validity 
The CIHR canadian HIV trials network mandate includes strengthening capacity to conduct and apply clinical research through training and mentoring initiatives of HIV researchers by building strong networks and partnerships on the African continent. At the17th International Conference on AIDS and Sexually Transmitted Infections in Africa (ICASA), the CTN facilitated a two-day workshop to address ethical issues in the conduct of HIV research, and career enhancing strategies for young African HIV researchers. Conference attendees were allowed to attend whichever session was of interest to them. We report on the topics covered, readings shared and participants’ evaluation of the workshop. The scientific aspects of ethical research in HIV and career enhancement strategies are relevant issues to conference attendees.
PMCID: PMC4315477  PMID: 25667706
Capacity building; ethics; HIV research; South Africa
14.  Methadone induces testosterone suppression in patients with opioid addiction 
Scientific Reports  2014;4:6189.
Sex hormones may have a role in the pathophysiology of substance use disorders, as demonstrated by the association between testosterone and addictive behaviour in opioid dependence. Although opioid use has been found to suppress testosterone levels in men and women, the extent of this effect and how it relates to methadone treatment for opioid dependence is unclear. The present multi-centre cross-sectional study consecutively recruited 231 patients with opioid dependence from methadone clinics across Ontario, Canada between June and December of 2011. We obtained demographic details, substance use, psychiatric history, and blood and urine samples from enrolled subjects. The control group included 783 non-opioid using adults recruited from a primary care setting in Ontario, Canada. Average testosterone level in men receiving methadone treatment was significantly lower than controls. No effect of opioids including methadone on testosterone level in women was found and testosterone did not fluctuate significantly between menstrual cycle phases. In methadone patients, testosterone level was significantly associated with methadone dose in men only. We recommend that testosterone levels be checked in men prior and during methadone and other opioid therapy, in order to detect and treat testosterone deficiency associated with opioids and lead to successful methadone treatment outcomes.
PMCID: PMC4143768  PMID: 25155550
15.  Genetic influence on methadone treatment outcomes in patients undergoing methadone maintenance treatment for opioid addiction: a pilot study 
Treatment of opioid addiction with methadone is effective; however, it is known to produce interindividual variability. This may be influenced in part by genetic variants, which can increase the initial risk of developing opioid addiction as well as explain differences in response to treatment. This pilot study aimed to assess the feasibility of conducting a full-scale genetic analysis to identify genes that predict methadone treatment outcomes in this population.
This was a cross-sectional observational study of patients admitted to a methadone maintenance treatment program for opioid addiction. We obtained demographic and clinical characteristics in addition to blood and urine samples, for the assessment of treatment outcomes.
The recruitment process yielded 252 patients, representing a 20% recruitment rate. We conducted genetic testing based on a 99.6% rate of provision of DNA samples. The average retention in treatment was 3.4 years, and >50% of the participants reported psychiatric and medical comorbidities. BDNF rs6265 and DRD2 rs1799978 were the common single nucleotide polymorphisms (SNPs) selected for the feasibility study.
This study met our predetermined feasibility criteria; recruitment, response rates, and genetic testing were feasible; treatment duration was sufficient for follow up; and the prevalence of comorbid conditions indicated the need for reliable psychiatric and chronic pain measures. The study strengths included effective collaboration with clinics and the generalizability of sample population. Key learning points show the need for assessment of treatment outcomes on multiple domains, implementation of follow up, and the development of standardized training for the study clinical staff.
PMCID: PMC4149396  PMID: 25187714
genetics; substitute opioid therapy; treatment response; risk factors
16.  Design, implementation, and evaluation of a pediatric and adolescent type 2 diabetes management program at a tertiary pediatric center 
Global rates of type 2 diabetes in children and adolescents have increased significantly over the past three decades. Type 2 diabetes is a relatively new disease in this age group, and there is a dearth of information about how to structure treatment programs to manage its comorbidities and complications. In this paper, we describe the design and implementation of a personalized multidisciplinary, family-centered, pediatric and adolescent type 2 diabetes program at a tertiary pediatric center in Hamilton, Ontario, Canada. We report the process of designing and implementing such a program, and show that this multidisciplinary program led to improvement in glycated hemoglobin (n=17, 8% at baseline versus 6.4% at 1 year, 95% confidence interval (0.1–0.28), P-value <0.0001) and stabilized body mass index, with lowered C-peptide and no change in fitness or metabolic biomarkers of lipid metabolism and liver function. As type 2 diabetes becomes more prevalent in youth, the need for programs that successfully address the complex nature of this disease is central to its management and to mitigate its long-term adverse outcomes.
PMCID: PMC4124128  PMID: 25114539
type 2 diabetes; pediatric; adolescents; program design; multidisciplinary
17.  Empirical comparison of four baseline covariate adjustment methods in analysis of continuous outcomes in randomized controlled trials 
Clinical Epidemiology  2014;6:227-235.
Although seemingly straightforward, the statistical comparison of a continuous variable in a randomized controlled trial that has both a pre- and posttreatment score presents an interesting challenge for trialists. We present here empirical application of four statistical methods (posttreatment scores with analysis of variance, analysis of covariance, change in scores, and percent change in scores), using data from a randomized controlled trial of postoperative pain in patients following total joint arthroplasty (the Morphine COnsumption in Joint Replacement Patients, With and Without GaBapentin Treatment, a RandomIzed ControlLEd Study [MOBILE] trials).
Analysis of covariance (ANCOVA) was used to adjust for baseline measures and to provide an unbiased estimate of the mean group difference of the 1-year postoperative knee flexion scores in knee arthroplasty patients. Robustness tests were done by comparing ANCOVA with three comparative methods: the posttreatment scores, change in scores, and percentage change from baseline.
All four methods showed similar direction of effect; however, ANCOVA (−3.9; 95% confidence interval [CI]: −9.5, 1.6; P=0.15) and the posttreatment score (−4.3; 95% CI: −9.8, 1.2; P=0.12) method provided the highest precision of estimate compared with the change score (−3.0; 95% CI: −9.9, 3.8; P=0.38) and percent change (−0.019; 95% CI: −0.087, 0.050; P=0.58).
ANCOVA, through both simulation and empirical studies, provides the best statistical estimation for analyzing continuous outcomes requiring covariate adjustment. Our empirical findings support the use of ANCOVA as an optimal method in both design and analysis of trials with a continuous primary outcome.
PMCID: PMC4105274  PMID: 25053894
ANOVA; ANCOVA; change score; knee arthroplasty
18.  Rapid paediatric fluid resuscitation: a randomised controlled trial comparing the efficiency of two provider-endorsed manual paediatric fluid resuscitation techniques in a simulated setting 
BMJ Open  2014;4(7):e005028.
Manual techniques of intravascular fluid administration are commonly used during paediatric resuscitation, although it is unclear which technique is most efficient in the hands of typical healthcare providers. We compared the rate of fluid administration achieved with the disconnect–reconnect and push–pull manual syringe techniques for paediatric fluid resuscitation in a simulated setting.
This study utilised a randomised crossover trial design and enrolled 16 consenting healthcare provider participants from a Canadian paediatric tertiary care centre. The study was conducted in a non-clinical setting using a model simulating a 15 kg child in decompensated shock. Participants administered 900 mL (60 mL/kg) of normal saline to the simulated patient using each of the two techniques under study. The primary outcome was the rate of fluid administration, as determined by two blinded independent video reviewers. We also collected participant demographic data and evaluated other secondary outcomes including total volume administered, number of catheter dislodgements, number of technical errors, and subjective and objective measures of provider fatigue.
All 16 participants completed the trial. The mean (SD) rate of fluid administration (mL/s) was greater for the disconnect–reconnect technique at 1.77 (0.145) than it was for the push–pull technique at 1.62 (0.226), with a mean difference of 0.15 (95% CI 0.055 to 0.251; p=0.005). There was no difference in mean volume administered (p=0.778) or participant self-reported fatigue (p=0.736) between techniques. No catheter dislodgement events occurred.
The disconnect–reconnect technique allowed for the fastest rate of fluid administration, suggesting that use of this technique may be preferable in situations requiring rapid resuscitation. These findings may help to inform future iterations of paediatric resuscitation guidelines.
Trial registration number
This trial was registered at [NCT01774214] prior to enrolling the first participant.
PMCID: PMC4091513  PMID: 24993757
19.  Performance of the high-sensitivity troponin assay in diagnosing acute myocardial infarction: systematic review and meta-analysis 
CMAJ Open  2014;2(3):E199-E207.
High-sensitivity cardiac troponin assays have been adopted by many clinical centres worldwide; however, clinicians are uncertain how to interpret the results. We sought to assess the utility of these assays in diagnosing acute myocardial infarction (MI).
We carried out a systematic review and meta-analysis of studies comparing high-sensitivity with conventional assays of cardiac troponin levels among adults with suspected acute MI in the emergency department. We searched MEDLINE, EMBASE and Cochrane databases up to April 2013 and used bivariable random-effects modelling to obtain summary parameters for diagnostic accuracy.
We identified 9 studies that assessed the use of high-sensitivity troponin T assays (n = 9186 patients). The summary sensitivity of these tests in diagnosing acute MI at presentation to the emergency department was estimated to be 0.94 (95% confidence interval [CI] 0.89–0.97); for conventional tests, it was 0.72 (95% CI 0.63–0.79). The summary specificity was 0.73 (95% CI 0.64–0.81) for the high-sensitivity assay compared with 0.95 (95% CI 0.93–0.97) for the conventional assay. The differences in estimates of the summary sensitivity and specificity between the high-sensitivity and conventional assays were statistically significant (p < 0.01). The area under the curve was similar for both tests carried out 3–6 hours after presentation. Three studies assessed the use of high-sensitivity troponin I assays and showed similar results.
Used at presentation to the emergency department, the high-sensitivity cardiac troponin assay has improved sensitivity, but reduced specificity, compared with the conventional troponin assay. With repeated measurements over 6 hours, the area under the curve is similar for both tests, indicating that the major advantage of the high-sensitivity test is early diagnosis.
PMCID: PMC4183183  PMID: 25295240
20.  Recruitment feasibility to a cohort study of endocrine and metabolic health among survivors of childhood brain tumours: a report from the Canadian study of Determinants of Endometabolic Health in ChIlDrEn (CanDECIDE) 
BMJ Open  2014;4(6):e005295.
The aim of this study was to test the feasibility of recruitment and performance of study procedures of the Canadian Study of Determinants of Endometabolic Health in ChIlDrEn (CanDECIDE) study, which was designed to assess the determinants of endocrine and metabolic health in survivors of childhood brain tumours.
A single paediatric tertiary care centre in Hamilton, Ontario, Canada.
We included boys and girls, aged 5 years and older, who were lean (body mass index (BMI) below 85th centile for age and gender) or overweight/obese (BMI 85th centile or above for age and gender). We excluded children on steroids or immunosuppressant therapy, smokers and those who had an active infection for the 2 weeks prior to participation.
Feasibility targets included recruitment rate of at least 50%, the consenting of 80% of participants to provide biological samples, 90% questionnaire completion rate and the ability to process biological samples from at least 80% of participants.
We approached 210 potential participants, and of the 112 (53%) who agreed to participate, 30 (26.8%) completed the study visit over 7 months. All participants agreed to fast, provide biological samples and complete the questionnaires. Sample collection was successful in 97% (29/30) of participants and laboratory procedures were feasible in 100% of collected samples. We also tested resources required for the conduct of the full study including personnel, space, laboratory equipment and procedures and determined that they are all feasible.
Recruitment and consenting of patients for the CanDECIDE study may be feasible. However, we are considering prolonging recruitment duration and collaboration with other centres to meet recruitment targets due to lower than expected recruitment rate. Completion of questionnaires and implementation of sample processing protocols are feasible.
PMCID: PMC4078774  PMID: 24969784
21.  Interim analysis for binary outcome trials with a long fixed follow-up time and repeated outcome assessments at pre-specified times 
SpringerPlus  2014;3:323.
In trials with binary outcomes, assessed repeatedly at pre-specified times and where the subject is considered to have experienced a failure at the first occurrence of the outcome, interim analyses are performed, generally, after half or more of the subjects have completed follow-up. Depending on the duration of accrual relative to the length of follow-up, this may be inefficient, since there is a possibility that the trial will have completed accrual prior to the interim analysis. An alternative is to plan the interim analysis after subjects have completed follow-up to a time that is less than the fixed full follow-up duration. Using simulations, we evaluated three methods to estimate the event proportion for the interim analysis in terms of type I and II errors and the probability of early stopping. We considered: 1) estimation of the event proportion based on subjects who have been followed for a pre-specified time (less than the full follow-up duration) or who experienced the outcome; 2) estimation of the event proportion based on data from all subjects that have been randomized by the time of the interim analysis; and 3) the Kaplan-Meier approach to estimate the event proportion at the time of the interim analysis. Our results show that all methods preserve and have comparable type I and II errors in certain scenarios. In these cases, we recommend using the Kaplan-Meier method because it incorporates all the available data and has greater probability of early stopping when the treatment effect exists.
PMCID: PMC4087327  PMID: 25019050
Interim analysis; Binary outcome; Power; Type I error
22.  The CANadian Pediatric Weight Management Registry (CANPWR): Study protocol 
BMC Pediatrics  2014;14:161.
Over recent decades, the prevalence of pediatric obesity has increased markedly in developed and developing countries, and the impact of obesity on health throughout the lifespan has led to urgent calls for action. Family-based weight management interventions that emphasize healthy lifestyle changes can lead to modest improvements in weight status of children with obesity. However, these interventions are generally short in duration, reported in the context of randomized controlled trials and there are few reports of outcomes of these treatment approaches in the clinical setting. Answering these questions is critical for improving the care of children with obesity accessing outpatient health services for weight management. In response, the CANadian Pediatric Weight management Registry (CANPWR) was designed with the following three primary aims:
1. Document changes in anthropometric, lifestyle, behavioural, and obesity-related co-morbidities in children enrolled in Canadian pediatric weight management programs over a three-year period;
2. Characterize the individual-, family-, and program-level determinants of change in anthropometric and obesity-related co-morbidities;
3. Examine the individual-, family-, and program-level determinants of program attrition.
This prospective cohort, multi-centre study will include children (2–17 years old; body mass index ≥85th percentile) enrolled in one of eight Canadian pediatric weight management centres. We will recruit 1,600 study participants over a three-year period. Data collection will occur at presentation and 6-, 12-, 24-, and 36-months follow-up. The primary study outcomes are BMI z-score and change in BMI z-score over time. Secondary outcomes include anthropometric (e.g., height, waist circumference,), cardiometabolic (e.g., blood pressure, lipid profile, glycemia), lifestyle (e.g., dietary intake, physical activity, sedentary activity), and psychosocial (e.g., health-related quality of life) variables. Potential determinants of change and program attrition will include individual-, family-, and program-level variables.
This study will enable our interdisciplinary team of clinicians, researchers, and trainees to address foundational issues regarding the management of pediatric obesity in Canada. It will also serve as a harmonized, evidence-based registry and platform for conducting future intervention research, which will ultimately enhance the weight management care provided to children with obesity and their families.
PMCID: PMC4082676  PMID: 24957705
Pediatric; Obesity; Family; Treatment; Canada; Health services
23.  Estimating treatment effects in randomised controlled trials with non-compliance: a simulation study 
BMJ Open  2014;4(6):e005362.
Randomised controlled trials (RCTs) are often considered as the gold standard for assessing new health interventions. Patients are randomly assigned to receive an intervention or control. The effect of the intervention can be estimated by comparing outcomes between groups, whose prognostic factors are expected to balance by randomisation. However, patients’ non-compliance with their assigned treatment will undermine randomisation and potentially bias the estimate of treatment effect. Through simulation, we aim to compare common approaches in analysing non-compliant data under different non-compliant scenarios.
Based on a real study, we simulated hypothetical trials by varying three non-compliant factors: the type, randomness and degree of non-compliance. We compared the intention-to-treat (ITT), as-treated (AT), per-protocol (PP), instrumental variable (IV) and complier average casual effect (CACE) analyses to estimate large (50% improvement over the control), moderate (25% improvement) and null (same as the control) treatment effects. Different approaches were compared by the bias of estimate, mean square error (MSE) and 95% coverage of the true value.
For a large or moderate treatment effect, the ITT estimate was considerably biased in all scenarios. The AT, PP, IV and CACE estimates were unbiased when non-compliant behaviours were random. The IV estimate was unbiased when non-compliant behaviours were symmetrically dependent on patients’ conditions. The PP estimate was mostly unbiased when patients in the control group did not have access to the intervention. When the intervention was not different from the control, the ITT was less biased than the other approaches. Similar results were found when comparing the MSE and 95% coverage.
The standard ITT analysis under non-compliance is biased when the intervention has a moderate or large effect. Alternative analyses can provide unbiased or less biased estimates. Based on the results, we make some suggestions on choosing optimal approaches for analysing specific non-compliant scenarios.
PMCID: PMC4067862  PMID: 24939814
24.  Fractures are increased and bisphosphonate use decreased in individuals with insulin-dependent diabetes: a 10 year cohort study 
Individuals with diabetes have been found previously to be at increased risk of non-traumatic fracture. However, it is unclear if these individuals are being identified and treated for osteoporosis.
7753 Canadians over 50 years of age were followed prospectively for 10 years. 606/7753 (7.8%) of had diabetes; 98 were insulin-dependent and 508 were not. Using a cox proportional hazards model, we assessed the association between diabetes status and incident non-traumatic fracture. Using logistic regression we identified factors associated with bisphosphonate use over the 10 year period of study.
Mean (SD) age of participants was 66.7(9.4) years and 72% were female. Those with diabetes had higher BMD T-scores at baseline, with a mean (SD) femoral neck T-Score of -0.97 (1.06), compared to -1.24 (0.99) in the general cohort. The adjusted hazard ratio (HR) for incident non-traumatic fracture in individuals with insulin-dependent diabetes over the 10 year study period was 2.50 (95% confidence interval [CI] 1.60, 3.90; p < 0.001). Despite this increased fracture rate, individuals with diabetes (insulin-dependent or non-insulin-dependent) were less likely to be on bisphosphonate therapy at any point over 10 years of prospective follow up compared to other CaMos subjects (odds ratio [OR]: 0.59; 95% CI 0.46-0.75, p < 0.001).
Despite the increased risk of non-traumatic fracture associated with insulin-dependent diabetes, we that found individuals with diabetes are less likely to be treated with a bisphosphonate than those without diabetes. These findings point to a possible care gap in the treatment of non-traumatic fractures in individuals with diabetes in Canada.
PMCID: PMC4065314  PMID: 24919660
Fracture; Diabetes; Insulin; Care gap; Treatment; Osteoporosis
25.  Outcomes after corrective surgery for congenital dextro-transposition of the great arteries using the arterial switch technique: a protocol for a scoping systematic review 
BMJ Open  2014;4(6):e005123.
Dextro-transposition of the great arteries (d-TGA) is a life-threatening congenital health defect that requires rapid surgery. The most widely used approach is the arterial switch operation (ASO) developed by Jatene in the 1970s. The first set of children who received this intervention are now adults. The objective of this scoping review of the literature was to document the short-term (less than 1 year), medium-term (1–20 years) and long-term (more than 20 years) outcomes in children who underwent the ASO. Our primary income is survival, but we will explore other secondary surgical, cardiovascular, reproductive and quality-of-life outcomes.
Methods and analyses
Using a systematic scoping review approach, we will conduct a systematic search of the published literature for experimental and observational studies published on children who received the ASO intervention for classic d-TGA. We will search MEDLINE, Excerpta Medica Database (EMBASE), Cumulative Index to Nursing and Allied Health Literature (CINAHL) and Literatura Latino Americana em Ciências da Saúde (LILACS) from 1973 (date of the first successful ASO) to February 2014. Identified articles will be screened in duplicate and full text for selected articles will be retrieved. Data extraction will be carried out in duplicate. Discrepancies will be resolved by consensus or by consulting a third author. Where possible, proportions will be pooled using the inverse variance method. Our findings will be reported according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) and Meta-analysis Of Observational studies in Epidemiology (MOOSE) guidelines.
Ethics and dissemination
The results of this paper will be disseminated as peer-reviewed publications, at conferences and at clinical rounds. Our findings may answer important questions for surgeons who perform the ASO intervention and for clinicians who take care of patients after surgery and throughout their lifespans.
Trial Registration number
PMCID: PMC4067827  PMID: 24919640

Results 1-25 (151)