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1.  Validation of a Quality-of-Life Measure for Deaf or Hard of Hearing Youth 
Quailty-of-life (QOL) measures targeting youth with hearing loss are useful in population needs assessment, educational placement, and program design and evaluation. This study assesses the cross-sectional validity of the Youth Quality of Life Instrument–Deaf and Hard of Hearing Module (YQOL-DHH).
Study Design
Instrument development and cross-sectional survey.
Recruitment through schools, professional organizations, clinics, and programs for youth who are deaf or hard of hearing.
Subjects and Methods
Thirty-five candidate items were administered to 230 adolescents aged 11 to 18 years: 49% female, 61% white, 11% mild hearing loss, 20% moderate/moderate-severe, 41% severe/profound, and 28% with cochlear implants. Participants completed individual or group-administered questionnaires by paper and pencil (58%), Web-based English (29%), American Sign Language (ASL) or Pidgin Signed English (PSE) (9%) on DVD, or interviewer-supervised ASL or PSE DVD (4%). The Children's Depression Inventory (CDI-S) was also completed. Factor structure, reliability, construct validity, and respondent burden were assessed.
Thirty-two Items were retained in the final instrument covering 3 domains: seif-acceptance/advocacy (14 items, Cronbach α = 0.84), perceived stigma (8 items, Cronbach α = 0.85), and participation (10 items, Cronbach α = 0.86). QOL was not significantly associated with hearing level. One-week test-retest coefficients were acceptable: self-acceptance/advocacy (0.70), perceived stigma (0.78), and participation (0.92). As predicted, the total CDI-S score was associated in the appropriate direction (P < .0001) with all YQOL-DHH domains. Time to complete the paper-and-pencil version was 12 minutes.
The YQOL-DHH shows good reliability and validity for assessing hearing-specific QOL in adolescents.
PMCID: PMC4199826  PMID: 21493349
hearing-impaired persons; deaf persons; quality of life; adolescent; childhood hearing loss
2.  Increases in physical activity may affect quality of life differently in men and women: The PACE project 
Obesity is associated with impaired quality of life (QoL), but less is known about physical activity. We investigated how decreases in body mass index (BMI) and increases in activity affect obesity-specific QoL and potential gender differences in associations.
In a large worksite-randomized trial of a multilevel intervention on diet and physical activity behaviors, we conducted a cohort analysis at two years of follow-up. Self-reported activity and Obesity and Weight-Loss Quality Of Life (OWLQOL) were analyzed for individual-level associations using linear mixed models accounting for random worksite effects.
Gender modified the BMI-OWLQOL relationship, so analyses were conducted for males and females separately. Adjusting for demographic confounders, baseline OWLQOL, and several worksite-level variables including intervention arm, a 1.9 unit decrease in BMI (the interquartile range) was associated with an OWLQOL increase of 1.7 (95% CI: 1.2, 2.2) in males and 3.6 (95% CI: 3.2, 4.0) in females. Similarly, a 23 unit increase in physical activity score was associated with an OWLQOL increase of 0.9 (95% CI: 0.5, 1.4) in males and 1.6 (95% CI: 1.0, 2.3) in females. Physical activity associations were attenuated when adjusting for change in BMI, but remained significant for women (mean BMI 27.8 kg/m2).
This is the first study to demonstrate that increasing physical activity may improve obesity-specific QoL to a greater extent in women, particularly among overweight women, independent of BMI. Results may inform the design of interventions tailored to women targeting well-being through messages of increasing physical activity.
PMCID: PMC3760977  PMID: 23504523
Body mass index; physical activity; quality of life; weight loss; women
3.  Feasibility of Using Pedometers to Measure Daily Step Counts in Cystic Fibrosis and an Assessment of its Responsiveness to Changes in Health State 
Evaluation of physical activity is integral to the assessment of daily physical function and a potential objective outcome measure for clinical trials. We evaluated the feasibility of using pedometers to measure physical activity in adolescents and adults with cystic fibrosis (CF) and assessed the responsiveness of its measurement to changes in health state.
Participants were recruited through two CF clinics in Seattle, WA. Subjects were instructed to use their pedometer for at least one ill and two well periods (each lasting 7 days). Step rate was calculated as steps per hour of use. Daily symptoms were also recorded using the CF Respiratory Symptom Diary (CFRSD). Generalized estimating equation linear regression was used to compare mean step rate between health states and by self-reported symptom category.
We enrolled 30 CF patients with a mean (±SD) age of 22 (±7) years and a mean forced expiratory volume in 1 second (FEV1) of 57% (±25%) predicted. The mean period step rate increased from 397 (95% CI 324 – 497) steps/hour when ill to 534 (95% CI 413 – 654) steps/hour when well (p=0.015). Pedometer-recorded step rate also correlated with self-reported physical activity items on the CFRSD.
Step rate measured with a pedometer correlates significantly with changes in health status and self-reported activity, and could be used as an outcome measure in CF.
PMCID: PMC4197911  PMID: 22226414
4.  Development of the Incontinence Utility Index: estimating population-based utilities associated with urinary problems from the Incontinence Quality of Life Questionnaire and Neurogenic Module 
Generic utility instruments may not fully capture the impact and consequences of urinary problems. Condition-specific preference-based measures, developed from previously validated disease-specific patient-reported outcomes instruments, may add relevant information for economic evaluations. The aim of this study was to develop a condition-specific preference-based measure, the Incontinence Utility Index (IUI), for valuing health states associated with urinary problems.
A two-step process was implemented. First, an abbreviated health state classification system was developed from the Incontinence Quality of Life Questionnaire (I-QOL) and Neurogenic Module by applying Rasch modelling, classical psychometrical testing and expert criteria to data from two pivotal trials comprised of neurogenic detrusor overactivity (NDO) patients. Criterion, convergent validity and concordance with the original instrument was assessed in the abbreviated version. Then, a multi-attribute utility function (MAUF) was estimated from a representative sample of the UK non-institutionalized adult general population. Visual analogue and time-trade off (TTO) evaluations were applied in the elicitation process. Predictive validity of the MAUF was tested comparing estimated and direct utility scores.
The abbreviated health state classification system generated from the NDO sample contained 5 attributes with 3 levels of response and had adequate psychometrical properties: significant differences in scores according to the reduction in the frequency of urinary incontinence episodes [UIE] (p < 0.001); Spearman correlation coefficient with number of daily UIE = −0.43; p < 0.01 and Intraclass Correlation Coefficient (ICC, 95% CI) with the original version = 0.90 (0.89-0.91; p < 0.001). Next, 442 participants were interviewed (398 cases were valid, generating 2,388 TTO evaluations) to estimate the social preferences for derived health states. Mean age was 44.75 years (interquartile range 33.5-55.5) and 60.1% were female. An overall algorithm for the IUI was estimated and transformed onto a dead = 0.00 and full health = 1.00 scale. Model fits were acceptable (R-squared = 0.923 and 0.978). Predictive validity was adequate: ICC (95% CI) = 0.928 (0.648-0.985) and Mean of Absolute Differences = 0.038.
The newly developed IUI is a preference-based measure for urinary problems related to NDO that provides general population-based utility scores with adequate predictive validity.
Trial registration NCT00461292, NCT00311376.
Electronic supplementary material
The online version of this article (doi:10.1186/s12955-014-0147-7) contains supplementary material, which is available to authorized users.
PMCID: PMC4196092  PMID: 25288099
Overactive bladder; Urinary incontinence; Utility; Preference; Quality of life; Multi-attribute theory
5.  Measurement Properties of the Chinese Version of the Youth Quality of Life Instrument–Weight Module (YQOL-W) 
PLoS ONE  2014;9(9):e109221.
Childhood obesity is a growing public health concern in China. It not only compromises physical health, but also has negative impacts on psychosocial well-being. As obesity rates increase, finding out what the perceptions of Chinese youth are regarding their weight is important for intervention planning and evaluation. However, there is a paucity of available obesity-specific instruments for children and adolescents in China and youth weight-specific quality of life (QOL) has been little reported. This study aimed to evaluate the measurement properties of the Chinese version of the Youth Quality of Life Instrument – Weight Module (YQOL-W).
The Chinese version of the YQOL-W was administered to 840 youth aged 11–18 from nine schools. Measurement properties including measurement model, reliability, validity and burden were evaluated.
Confirmatory factor analysis showed that a three-factor model had acceptable model fit. The instrument had robust internal consistency reliability with Cronbach's α ranging from 0.84 to 0.96 and acceptable test-retest reliability with the intraclass correlation coefficients (ICCs) all higher than 0.7. The standard error of measurement (SEM) values for the Self, Social and Environment factors and total score were 10.352, 9.526, 12.086 and 8.425, respectively. The small real differences (SRDs) for the Self, Social and Environment factors and total score were 28.675, 26.387, 33.478, and 23.337, respectively. The Pearson's correlation coefficients between the YQOL-W and the PedsQL4.0 General Core Scales were stronger between comparable dimensions than those between less comparable dimensions, demonstrating convergent and discriminant evidence of construct validity. Significant differences were found in subscale and total scores across weight status, age and genders (P<0.01), supporting the known-groups validity of the instrument.
The Chinese version of the YQOL-W has acceptable measurement properties and can be used to assess the weight-specific QOL of children and adolescents in China.
PMCID: PMC4182632  PMID: 25268884
6.  Comparative effectiveness of next generation genomic sequencing for disease diagnosis: Design of a randomized controlled trial in patients with colorectal cancer/polyposis syndromes✩ 
Whole exome and whole genome sequencing are applications of next generation sequencing transforming clinical care, but there is little evidence whether these tests improve patient outcomes or if they are cost effective compared to current standard of care. These gaps in knowledge can be addressed by comparative effectiveness and patient-centered outcomes research. We designed a randomized controlled trial that incorporates these research methods to evaluate whole exome sequencing compared to usual care in patients being evaluated for hereditary colorectal cancer and polyposis syndromes. Approximately 220 patients will be randomized and followed for 12 months after return of genomic findings. Patients will receive findings associated with colorectal cancer in a first return of result visit, and findings not associated with colorectal cancer (incidental findings) during a second return of result visit. The primary outcome is efficacy to detect mutations associated with these syndromes; secondary outcomes include psychosocial impact, cost-effectiveness and comparative costs. The secondary outcomes will be obtained via surveys before and after each return visit. The expected challenges in conducting this randomized controlled trial include the relatively low prevalence of genetic disease, difficult interpretation of some genetic variants, and uncertainty about which incidental findings should be returned to patients. The approaches utilized in this study may help guide other investigators in clinical genomics to identify useful outcome measures and strategies to address comparative effectiveness questions about the clinical implementation of genomic sequencing in clinical care.
PMCID: PMC4175052  PMID: 24997220
Comparative effectiveness research; Genomics; Next generation sequencing; Randomized clinical trial; Outcomes research; Whole exome sequencing
7.  Patient-reported outcomes in meta-analyses --Part 2: methods for improving interpretability for decision-makers 
Systematic reviews and meta-analyses of randomized trials that include patient-reported outcomes (PROs) often provide crucial information for patients, clinicians and policy-makers facing challenging health care decisions. Based on emerging methods, guidance on improving the interpretability of meta-analysis of patient-reported outcomes, typically continuous in nature, is likely to enhance decision-making. The objective of this paper is to summarize approaches to enhancing the interpretability of pooled estimates of PROs in meta-analyses. When differences in PROs between groups are statistically significant, decision-makers must be able to interpret the magnitude of effect. This is challenging when, as is often the case, clinical trial investigators use different measurement instruments for the same construct within and between individual randomized trials. For such cases, in addition to pooling results as a standardized mean difference, we recommend that systematic review authors use other methods to present results such as relative (relative risk, odds ratio) or absolute (risk difference) dichotomized treatment effects, complimented by presentation in either: natural units (e.g. overall depression reduced by 2.4 points when measured on a 50-point Hamilton Rating Scale for Depression); minimal important difference units (e.g. where 1.0 unit represents the smallest difference in depression that patients, on average, perceive as important the depression score was 0.38 (95% CI 0.30 to 0.47) units less than the control group); or a ratio of means (e.g. where the mean in the treatment group is divided by the mean in the control group, the ratio of means is 1.27, representing a 27% relative reduction in the mean depression score).
PMCID: PMC3984637  PMID: 24359184
8.  Evaluation of the Irritable Bowel Syndrome Quality of Life (IBS-QOL) questionnaire in diarrheal-predominant irritable bowel syndrome patients 
Diarrhea-predominant irritable bowel syndrome (IBS-d) significantly diminishes the health-related quality of life (HRQOL) of patients. Psychological and social impacts are common with many IBS-d patients reporting comorbid depression, anxiety, decreased intimacy, and lost working days. The Irritable Bowel Syndrome Quality of Life (IBS-QOL) questionnaire is a 34-item instrument developed and validated for measurement of HRQOL in non-subtyped IBS patients. The current paper assesses this previously-validated instrument employing data collected from 754 patients who participated in a randomized clinical trial of a novel treatment, eluxadoline, for IBS-d.
Psychometric methods common to HRQOL research were employed to evaluate the IBS-QOL. Many of the historical analyses of the IBS-QOL validations were used. Other techniques that extended the original methods were applied where more appropriate for the current dataset. In IBS-d patients, we analyzed the items and substructure of the IBS-QOL via item reduction, factor structure, internal consistency, reproducibility, construct validity, and ability to detect change.
This study supports the IBS-QOL as a psychometrically valid measure. Factor analyses suggested that IBS-specific QOL as measured by the IBS-QOL is a unidimensional construct. Construct validity was further buttressed by significant correlations between IBS-QOL total scores and related measures of IBS-d severity including the historically-relevant Irritable Bowel Syndrome Adequate Relief (IBS-AR) item and the FDA’s Clinical Responder definition. The IBS-QOL also showed a significant ability to detect change as evidenced by analysis of treatment effects. A minority of the items, unrelated to the IBS-d, performed less well by the standards set by the original authors.
We established that the IBS-QOL total score is a psychometrically valid measure of HRQOL in IBS-d patients enrolled in this study. Our analyses suggest that the IBS-QOL items demonstrate very good construct validity and ability to detect changes due to treatment effects. Furthermore, our analyses suggest that the IBS-QOL items measure a univariate construct and we believe further modeling of the IBS-QOL from an item response theory (IRT) approach under both non-treatment and treatment conditions would greatly further our understanding as item-based methods could be used to develop a short form.
PMCID: PMC3895767  PMID: 24330412
IBS-QOL; Patient-reported Outcomes; Psychometrics; HRQOL; Irritable Bowel Syndrome; Diarrhea; Eluxadoline
9.  Managed Care, Access to Specialists, and Outcomes among Primary Care Patients with Pain 
Health Services Research  2003;38(1 Pt 1):1-19.
To determine whether managed care controls were associated with reduced access to specialists and worse outcomes among primary care patients with pain.
Data Sources/Study Setting
Patient, physician, and office manager questionnaires collected in the Seattle area in 1996–1997, plus data abstracted from patient records and health plans.
Study Design
A prospective cohort study of 2,275 adult patients with common pain problems recruited in the offices of 261 primary care physicians in Seattle.
Data Collection
Patients completed a waiting room questionnaire and follow-up surveys at the end of the first and sixth months to measure access to specialists and outcomes. Intensity of managed care controls measured by plan managed care index and benefit/cost-sharing indexes, office managed care index, physician compensation, financial incentives, and use of clinical guidelines.
Principal Findings
A financial withhold for referral was associated with a lower likelihood of referral to a physician specialist, a greater likelihood of seeing a specialist without referral, and a lower patient rating of care from the primary physician. Otherwise, patients in more managed offices and with greater out-of-network plan benefits had greater access to specialists. Patients with more versus less managed care had similar health outcomes, but patients in more managed offices had lower ratings of care provided by their primary physicians.
Increased managed care controls were generally not associated with reduced access to specialists and worse health outcomes for primary care patients with pain, but patients in more managed offices had lower ratings of care provided by their primary physicians.
PMCID: PMC1360871  PMID: 12650378
Managed care programs; pain, primary care; specialties (medical); referral; consultation; outcome assessment
10.  Dietary and physical activity behaviors related to obesity-specific quality of life and work productivity: baseline results from a worksite trial 
The British journal of nutrition  2011;108(6):1134-1142.
Obesity is associated with impaired health-related quality of life (QoL) and reduced productivity; less is known about the effect of dietary factors. This study investigated how dietary behaviors, physical activity, and Body Mass Index (BMI) relate to weight-specific QoL and work productivity. The study was conducted in 31 small blue-collar and service industry worksites in Seattle. Participants were 747 employees (33.5% non-White). Measures included self-reported servings of fruits and vegetables, dietary behaviors such as fast food consumption, Godin free-time physical activity scores, measured height and weight, Obesity and Weight Loss Quality of Life (OWLQOL) scores, and Work Limitations Questionnaire (WLQ) scores. Baseline data were analyzed using linear mixed models separately for men (n=348) and women (n=399), since gender modified the effects. BMI was negatively associated with OWLQOL in both women (p<0.001) and men (p<0.001). The linear effect estimate for OWLQOL score associated with one-category increase in BMI was 30% (95% CI: 25%, 44%) for women and 14% (95% CI: 10%, 17%) for men. BMI was positively associated with productivity loss only in women (exp(slope)=1.46, 95% CI: 1.02, 2.11, p=0.04). Eating while doing another activity was negatively associated with OWLQOL scores in men (p=0.0006, independent of BMI) and with productivity in women (p=0.04, effect diminished when adjusting for BMI). Fast food meals were associated with decreased productivity for men (p=0.038, independent of BMI). Results suggest the obesogenic dietary behaviors and higher BMI are associated with decreased QoL and productivity variously in women and men.
PMCID: PMC3359391  PMID: 22142517
Dietary behaviors; Obesity; Quality of Life; Work productivity
11.  Health-Related Quality-of-Life Findings for the Prostate Cancer Prevention Trial 
The Prostate Cancer Prevention Trial (PCPT)—a randomized placebo-controlled study of the efficacy of finasteride in preventing prostate cancer—offered the opportunity to prospectively study effects of finasteride and other covariates on the health-related quality of life of participants in a multiyear trial.
We assessed three health-related quality-of-life domains (measured with the Health Survey Short Form–36: Physical Functioning, Mental Health, and Vitality scales) via questionnaires completed by PCPT participants at enrollment (3 months before randomization), at 6 months after randomization, and annually for 7 years. Covariate data obtained at enrollment from patient-completed questionnaires were included in our model. Mixed-effects model analyses and a cross-sectional presentation at three time points began at 6 months after randomization. All statistical tests were two-sided.
For the physical function outcome (n = 16 077), neither the finasteride main effect nor the finasteride interaction with time were statistically significant. The effects of finasteride on physical function were minor and accounted for less than a 1-point difference over time in Physical Functioning scores (mixed-effect estimate = 0.07, 95% confidence interval [CI] = −0.28 to 0.42, P = .71). Comorbidities such as congestive heart failure (estimate = −5.64, 95% CI = −7.96 to −3.32, P < .001), leg pain (estimate = −2.57, 95% CI = −3.04 to −2.10, P < .001), and diabetes (estimate = −1.31, 95% CI = −2.04 to −0.57, P < .001) had statistically significant negative effects on physical function, as did current smoking (estimate = −2.34, 95% CI = −2.97 to −1.71, P < .001) and time on study (estimate = −1.20, 95% CI = −1.36 to −1.03, P < .001). Finasteride did not have a statistically significant effect on the other two dependent variables, mental health and vitality, either in the mixed-effects analyses or in the cross-sectional analysis at any of the three time points.
Finasteride did not negatively affect SF–36 Physical Functioning, Mental Health, or Vitality scores.
PMCID: PMC3529595  PMID: 22972968
12.  Patient-reported outcomes in meta-analyses – Part 1: assessing risk of bias and combining outcomes 
Systematic reviews and meta-analyses of randomized trials that include patient-reported outcomes (PROs) often provide crucial information for patients and clinicians facing challenging health care decisions. Based on emerging methods, guidance on combining PROs in meta-analysis is likely to enhance their usefulness.
The objectives of this paper are: i) to describe PROs and why they are important for health care decision-making, ii) illustrate the key risk of bias issues that systematic reviewers should consider and, iii) address outcome characteristics of PROs and provide guidance for combining outcomes.
We suggest a step-by-step approach to addressing issues of PROs in meta-analyses. Systematic reviewers should begin by asking themselves if trials have addressed all the important effects of treatment on patients’ quality of life. If the trials have addressed PROs, have investigators chosen the appropriate instruments? In particular, does evidence suggest the PROs used are valid and responsive, and is the review free of outcome reporting bias? Systematic reviewers must then decide how to categorize PROs and when to pool results.
PMCID: PMC3708764  PMID: 23815754
Patient-reported outcomes; Health-related quality of life; Meta-analysis; Systematic review; Health care decision-making
13.  Development and validation of the self-management profile for type 2 diabetes (SMP-T2D) 
This study evaluated the measurement properties of a newly developed instrument – the Self-Management Profile for Type 2 Diabetes (SMP-T2D).
The 18-item SMP-T2D assesses 12 constructs: level and perceived ease of performance in five self-care domains (blood glucose monitoring, medication-taking, healthy eating, being physically active, and coping), and two global constructs (ease of weight management, confidence with ability to manage diabetes). Validation analyses were based on two studies involving 240 patients with T2D, Study 1 ( #NCT00637273) with SMP-T2D administration supplemented by SMP-T2D retest one week later, and Study 2 (Clinical #NCT00877890) with SMP-T2D administration supplemented by 24-week SMP-T2D follow-up after medication change. Validation included clinical indicators and measures of patient reported quality of life, psychological well-being and treatment outcomes.
All multi-item SMP-T2D measures showed acceptable internal consistency (alphas = 0.71 to 0.87); ten measures had test-retest reliability >0.75. Correlations among SMP-T2D measures and between SMP-T2D measures and validation measures, which were as hypothesized, provided evidence of convergent and discriminant validity. Scores for six SMP-T2D measures improved significantly during Study 2. Multiple regression analysis showed independent associations between change in SMP-T2D measures and change in trial outcomes from baseline to end-of-study.
Two studies provide preliminary evidence regarding the reliability, validity and responsiveness of the SMP-T2D. Further research on the utility of the instrument is needed.
PMCID: PMC3541081  PMID: 23039868
14.  Patient-reported outcome instruments used to assess pain and functioning in studies of bisphosphonate treatment for bone metastases 
Supportive Care in Cancer  2012;20(4):657-677.
When treating metastatic bone disease, relief of bone pain is often a key outcome. Because pain cannot be quantified with objective clinical measures, patient-reported outcome (PRO) measures are required to assess patients' subjective experience. The goal of the current review was to examine measures used to assess pain, as well as the impact of pain on functional status and health-related quality of life (HRQL), in trials of bisphosphonates for the treatment of bone metastases.
A literature search focused on articles published from January 1999 to April 2009.
A total of 49 articles were located that used PROs to assess pain-related outcomes of bisphosphonate treatment for bone metastases. The Brief Pain Inventory was the most commonly used multi-item instrument. However, the most common approach for assessing pain was to administer a single-item scale such as a visual analog scale, numerical rating scale, or verbal rating scale. Of the 49 studies, 19 included a PRO assessing functional status or HRQL.
Although pain is an important outcome of trials examining treatment for bone metastases, the current review suggests that there is little consistency in PRO measurement across studies. Furthermore, presentation of measures often lacked clear description, information on measurement properties, citations, clarity regarding method of administration, and consistent instrument names. Recommendations are provided for instrument validation within the target population, assessment of content validity, use of PRO instruments recently developed for patients with bone metastases, clear description of instruments, and implementation of measures consistent with recommendations from instrument developers.
PMCID: PMC3297753  PMID: 22302082
Bisphosphonate; Bone metastases; Bone pain; Patient-reported outcomes; Pain assessment
15.  Inter-rater agreement and reliability of the COSMIN (COnsensus-based Standards for the selection of health status Measurement Instruments) Checklist 
The COSMIN checklist is a tool for evaluating the methodological quality of studies on measurement properties of health-related patient-reported outcomes. The aim of this study is to determine the inter-rater agreement and reliability of each item score of the COSMIN checklist (n = 114).
75 articles evaluating measurement properties were randomly selected from the bibliographic database compiled by the Patient-Reported Outcome Measurement Group, Oxford, UK. Raters were asked to assess the methodological quality of three articles, using the COSMIN checklist. In a one-way design, percentage agreement and intraclass kappa coefficients or quadratic-weighted kappa coefficients were calculated for each item.
88 raters participated. Of the 75 selected articles, 26 articles were rated by four to six participants, and 49 by two or three participants. Overall, percentage agreement was appropriate (68% was above 80% agreement), and the kappa coefficients for the COSMIN items were low (61% was below 0.40, 6% was above 0.75). Reasons for low inter-rater agreement were need for subjective judgement, and accustom to different standards, terminology and definitions.
Results indicated that raters often choose the same response option, but that it is difficult on item level to distinguish between articles. When using the COSMIN checklist in a systematic review, we recommend getting some training and experience, completing it by two independent raters, and reaching consensus on one final rating. Instructions for using the checklist are improved.
PMCID: PMC2957386  PMID: 20860789
16.  Measurement properties of a multicultural weight-specific quality-of-life instrument for children and adolescents 
Quality of Life Research  2010;20(2):215-224.
To evaluate the psychometric properties of a new multicultural weight-specific quality-of-life (QOL) measure for children and adolescents–Youth Quality-of-Life Instrument–Weight module (YQOL-W).
Twenty-five candidate items were administered to 443 children and adolescents between 11 and 18 years of age, of whom 53% were female, 33% were white, 30% were African American and 37% were Mexican American. Thirty-four percent had a healthy body mass index (BMI), 20% were overweight and 46% were obese.
Twenty-one of the original 25 candidate items were retained in the final instrument. Exploratory and confirmatory factor analyses (CFA) resulted in a one-factor (21 items, alpha = 0.97) and a three-factor model including a Self factor (4 items, alpha = 0.90), a Social factor (11 items, alpha = 0.95) and an Environment factor (5 items, alpha = 0.90). CFA found the three-factor model had better model fit (P < 0.05). Both the one-factor and three-factor scores were negatively correlated with BMI and the Children’s Depression Inventory and positively correlated with generic quality of life, all at the P < 0.05 level. The 1-week test–retest intra-class correlation coefficients were 0.73 for Social, 0.71 for Self, 0.73 Environment and 0.77 for the one-factor model.
The YQOL-W shows good reliability and validity for assessing weight-specific QOL in children and adolescents.
PMCID: PMC3040311  PMID: 20820926
Quality of life; Obesity; Children; Adolescents; Minority health; Hispanic American; African American
17.  Reply to Letter to the Editor 
PMCID: PMC2902785  PMID: 20640039
18.  The Use of Patient-Reported Outcomes Instruments in Registered Clinical Trials: Evidence from 
Contemporary clinical trials  2009;30(4):289-292.
Investigators of clinical trials in which the list of outcomes include patient-reported outcomes (PROs) - usually labeled quality of life (QoL) - have a large number of instruments from which to choose. The extent and manner in which PRO instruments are used in clinical trials can be assessed using data from clinical trial registries. Most medical journals now require a clinical trial be registered before its results are considered for publication. This requirement is intended to discourage publication bias, such as the reporting of tests of hypotheses different from those stipulated at the start of the trial and selective reporting of partial results.
To assess the usage of PRO instruments in registered trials by various trial characteristics and to determine if the instruments are adequately identified in the registry.
A local copy of the database was made in September 2007. The outcomes of all interventional trials registered since September 2004 were assessed for usage of a PRO instrument. Odds ratios of PRO usage were estimated by a logistic regression model.
Of 17,704 interventional trials, 2,481 (14.0%) used at least one PRO instrument. However, less than half of those trials (41.0%) identified the instrument to be used. PRO usage is positively associated with phase (III), randomization type (randomized), intervention type (behavior) and sponsorship type (university/research organization).
PRO instruments are used in a significant percentage but minority of clinical trials. Trial registries should require that all PRO instruments be identified, including the concepts or outcomes they are intended to measure.
PMCID: PMC2683916  PMID: 19275948
patient-reported outcomes; quality of life; clinical trial registration; publication bias
19.  Might Massage or Guided Meditation Provide “Means to a Better End”? Primary Outcomes from an Efficacy Trial with Patients at the End of Life 
Journal of palliative care  2009;25(2):100-108.
This article reports findings from a randomized controlled trial of massage and guided meditation with patients at the end of life. Using data from 167 randomized patients, the authors consider patient outcomes through 10 weeks post-enrollment, as well as next-of-kin ratings of the quality of the final week of life for 106 patients who died during study participation. Multiple regression models demonstrated no significant treatment effects of either massage or guided meditation, delivered up to twice a week, when compared with outcomes of an active control group that received visits from hospice-trained volunteers on a schedule similar to that of the active treatment arms. The authors discuss the implications of their findings for integration of these complementary and alternative medicine therapies into standard hospice care.
PMCID: PMC2858762  PMID: 19678461
20.  The Establishment of the GENEQOL Consortium to Investigate the Genetic Disposition of Patient-Reported Quality-of-Life Outcomes 
To our knowledge, no comprehensive, interdisciplinary initiatives have been taken to examine the role of genetic variants on patient-reported quality-of-life outcomes. The overall objective of this paper is to describe the establishment of an international and interdisciplinary consortium, the GENEQOL Consortium, which intends to investigate the genetic disposition of patient-reported quality-of-life outcomes. We have identified five primary patient-reported quality-of-life outcomes as initial targets: negative psychological affect, positive psychological affect, self-rated physical health, pain, and fatigue. The first tangible objective of the GENEQOL Consortium is to develop a list of potential biological pathways, genes and genetic variants involved in these quality-of-life outcomes, by reviewing current genetic knowledge. The second objective is to design a research agenda to investigate and validate those genes and genetic variants of patient-reported quality-of-life outcomes, by creating large datasets. During its first meeting, the Consortium has discussed draft summary documents addressing these questions for each patient-reported quality-of-life outcome. A summary of the primary pathways and robust findings of the genetic variants involved is presented here. The research agenda outlines possible research objectives and approaches to examine these and new quality-of-life domains. Intriguing questions arising from this endeavor are discussed. Insight into the genetic versus environmental components of patient-reported quality-of-life outcomes will ultimately allow us to explore new pathways for improving patient care. If we can identify patients who are susceptible to poor quality of life, we will be able to better target specific clinical interventions to enhance their quality of life and treatment outcomes.
PMCID: PMC2824176  PMID: 19456223
21.  The COSMIN checklist for evaluating the methodological quality of studies on measurement properties: A clarification of its content 
The COSMIN checklist (COnsensus-based Standards for the selection of health status Measurement INstruments) was developed in an international Delphi study to evaluate the methodological quality of studies on measurement properties of health-related patient reported outcomes (HR-PROs). In this paper, we explain our choices for the design requirements and preferred statistical methods for which no evidence is available in the literature or on which the Delphi panel members had substantial discussion.
The issues described in this paper are a reflection of the Delphi process in which 43 panel members participated.
The topics discussed are internal consistency (relevance for reflective and formative models, and distinction with unidimensionality), content validity (judging relevance and comprehensiveness), hypotheses testing as an aspect of construct validity (specificity of hypotheses), criterion validity (relevance for PROs), and responsiveness (concept and relation to validity, and (in) appropriate measures).
We expect that this paper will contribute to a better understanding of the rationale behind the items, thereby enhancing the acceptance and use of the COSMIN checklist.
PMCID: PMC2848183  PMID: 20298572
22.  The COSMIN checklist for assessing the methodological quality of studies on measurement properties of health status measurement instruments: an international Delphi study 
Quality of Life Research  2010;19(4):539-549.
Aim of the COSMIN study (COnsensus-based Standards for the selection of health status Measurement INstruments) was to develop a consensus-based checklist to evaluate the methodological quality of studies on measurement properties. We present the COSMIN checklist and the agreement of the panel on the items of the checklist.
A four-round Delphi study was performed with international experts (psychologists, epidemiologists, statisticians and clinicians). Of the 91 invited experts, 57 agreed to participate (63%). Panel members were asked to rate their (dis)agreement with each proposal on a five-point scale. Consensus was considered to be reached when at least 67% of the panel members indicated ‘agree’ or ‘strongly agree’.
Consensus was reached on the inclusion of the following measurement properties: internal consistency, reliability, measurement error, content validity (including face validity), construct validity (including structural validity, hypotheses testing and cross-cultural validity), criterion validity, responsiveness, and interpretability. The latter was not considered a measurement property. The panel also reached consensus on how these properties should be assessed.
The resulting COSMIN checklist could be useful when selecting a measurement instrument, peer-reviewing a manuscript, designing or reporting a study on measurement properties, or for educational purposes.
PMCID: PMC2852520  PMID: 20169472
Delphi technique; Outcome assessment; Psychometrics; Quality of life; Questionnaire
23.  Shared Priorities for the End-of-Life Period 
This study investigated end-of-life priorities of terminally ill patients and their intimate associates. A primary goal was to reduce the number of items in an existing instrument measuring survivors’ evaluations of the quality of dying and death. Three Seattle-area patient samples (chronic obstructive pulmonary disease patients, hospice patients, and participants in an efficacy trial of complementary comfort care) and their significant others provided priority rankings of 26 experiences at end of life. Two items represented top priorities for all subgroups: time with family/friends and pain control. Clustered multivariate probit regression models suggested only a few significant differences between participant groups in priority rankings: higher education increased the priority placed on having available means to hasten death; cancer patients and persons in the hospice sample (likely those experiencing disproportionate pain) assigned pain control higher priority than other groups; persons in the clinical trial (which included massage as an intervention) assigned higher priority to human touch; racial/ethnic minorities emphasized the importance of having funeral arrangements made. In the clinical trial sample (the most recently interviewed), the importance attributed to taking care of health care costs increased over time. If researchers were to use a reduced set of the 17 items mentioned among the top five priorities by at least 10% of the sample, none of the items that varied significantly between subgroups or over time would be eliminated. This change would reduce respondent burden in future investigations, simplify analyses aimed at identifying domains underlying the dying and death experience, and exclude the top-priority item of fewer than 4% of respondents.
PMCID: PMC2746763  PMID: 18722084
End of life; patient preferences; palliative care; quality of life; quality of dying and death; priority ratings; pain control; psychosocial needs
24.  Assessment of Community Functioning in People With Schizophrenia and Other Severe Mental Illnesses: A White Paper Based on an NIMH-Sponsored Workshop 
Schizophrenia Bulletin  2006;33(3):805-822.
People with schizophrenia frequently have significant problems in community functioning. Progress in developing effective interventions to ameliorate these problems has been slowed by the absence of reliable and valid measures that are suitable for use in clinical trials. The National Institute of Mental Health convened a workgroup in September 2005 to examine this issue and make recommendations to the field that would foster research in this area. This article reports on issues raised at the meeting. Many instruments have been developed to assess community functioning, but overall insufficient attention has been paid to psychometric issues and many instruments are not suitable for use in clinical trials. Consumer self-report, informant report, ratings by clinicians and trained raters, and behavioral assessment all can provide useful and valid information in some circumstances and may be practical for use in clinical trials. However, insufficient attention has been paid to when and how different forms of assessment and sources of information are useful or how to understand inconsistencies. A major limiting factor in development of reliable and valid instruments is failure to develop a suitable model of functioning and its primary mediators and moderators. Several examples that can guide thinking are presented. Finally, the field is limited by the absence of an objective gold standard of community functioning. Hence, outcomes must be evaluated in part by “clinical significance.” This criterion is problematic because different observers and constituencies often have different opinions about what types of change are clinically important and how much change is significant.
PMCID: PMC2526156  PMID: 16931542
schizophrenia; assessment; outcomes
25.  The Tobacco Industry's Response to the COMMIT Trial: An Analysis of Legacy Tobacco Documents 
Public Health Reports  2006;121(5):501-508.
We analyzed internal tobacco industry documents that describe the industry's response to the Community Intervention Trial for Smoking Cessation (COMMIT), a multi-center community-based tobacco intervention project funded by the National Cancer Institute from 1988 to 1992. Our analysis of documents from the Legacy Tobacco Documents Library ( suggests that the tobacco industry reacted to COMMIT by (1) closely monitoring trial activities, (2) confronting COMMIT in communities where it was most active, (3) distorting COMMIT findings on underage smoking data reported in the media, and (4) using COMMIT activities as practice to strengthen their attack against the subsequent ASSIST trial, falsely accusing both studies of illegal political lobbying with taxpayers' money.
The tobacco industry closely monitored COMMIT activities and organized local responses to findings and activities perceived as threatening to the industry's public image or interests. Although we could not document a concerted attack by the tobacco industry that impacted the results of the COMMIT trial, data suggest that the industry used COMMIT as a learning opportunity to mount a well orchestrated and potentially damaging response to the larger American Stop Smoking Intervention Study for Cancer Prevention Trial.
PMCID: PMC1564446  PMID: 16972502

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