Developing a New Version of the SF-6D Health State Classification System From the SF-36v2: SF-6Dv2.

OBJECTIVE: The objective of this study was to develop the classification system for version of the SF-6D (SF-6Dv2) from the SF-36v2. SF-6Dv2 is an improved version of SF-6D, one of the most widely used generic measures of health for the calculation of quality-adjusted life years. STUDY DESIGN AND SETTING: A 3-step process was undertaken to generate a new classification system: (1) factor analysis to establish dimensionality; (2) Rasch analysis to understand item performance; and (3) tests of differential item function. To evaluate robustness, Rasch analyses were performed in multiple subsets of 2 large cross-sectional datasets from recently discharged hospital patients and online patient samples. RESULTS: On the basis of factor analysis, other psychometric evidence, cross-cultural considerations, and amenability to valuation, the 6-dimension classification used in SF-6D was maintained. SF-6Dv2 resulted in the following modifications to SF-6D: a simpler classification of physical function with clearer separation between levels; a more detailed 5-level description of role limitations; using negative wording to describe vitality; and using pain severity rather than pain interference. CONCLUSIONS: The SF-6Dv2 classification system describes more distinct levels of health than SF-6D, changes the descriptions used for a number of dimensions and provides clearer wording for health state valuation. The second stage of the study has developed a utility value set using discrete choice methods so that the measure can be used in health technology assessment. Further work should investigate the psychometric characteristics of the new instrument.

The Danish Psychosocial Work Environment Questionnaire (DPQ): Development, content, reliability and validity.

Objectives The aim of this study was to describe the development and the content of the Danish Psychosocial Work Environment Questionnaire (DPQ) and to test its reliability and validity. Methods We describe the identification of dimensions, the development of items, and the qualitative and quantitative tests of the reliability and validity of the DPQ. Reliability and validity of a 150 item version of the DPQ was evaluated in a stratified sample of 8958 employees in 14 job groups of which 4340 responded. Reliability was investigated using internal consistency and test-retest reliability. The factorial validity was investigated using confirmatory factor analysis (CFA). For each multi-item scale, we undertook CFA within each job group and multi-group CFA to investigate factorial invariance across job groups. Finally, using multi-group multi-factor CFA, we investigated whether scales were empirically distinct. Results Internal consistency reliabilities and test-retest reliabilities were satisfactory. Factorial validity of the multi-item scales was satisfactory within each of the 14 job groups. Factorial invariance was demonstrated for 10 of the 28 multi-item scales. The hypothesis that the scales of the DPQ were empirically distinct was supported. The final DPQ version consisted of 119 items covering 38 different psychosocial work environment dimensions. Conclusions Overall, the DPQ is a reliable and valid instrument for assessing psychosocial working conditions in a variety of job groups. The results indicate, however, that questions about psychosocial working conditions may be understood differently across job groups, which may have implications for the comparability of questionnaire-based measures of psychosocial working conditions across job groups.

Prospective assessment of the quality of life before, during and after image guided intensity modulated radiotherapy for prostate cancer.

BACKGROUND: Radiotherapy (RT) in combination with androgen deprivation therapy (ADT) for prostate cancer (PCa) carries a risk of gastrointestinal (GI) and genitourinary toxicity, which might affect the quality of life (QoL). The purpose of this study was to assess the QoL in patients with PCa before, during and after radiotherapy (RT) and to compare the QoL 1 year after RT to a normal population. METHODS: The QoL was evaluated prospectively by the self-administered questionnaire SF-36 in 87 patients with PCa. The SF-36 was completed before RT (baseline), at start of RT, at end of RT and 1 year after RT. A mixed model analysis was used to determine the changes in QoL at each time point compared to baseline. The patients' QoL 1 year after RT was compared to a normal population consisting of 462 reference subjects matched on age and education. RESULTS: One year after RT, patients reported significantly less pain and significantly fewer limitations due to their physical health compared to baseline. Compared to the normal population, patients reported significantly less pain 1 year after RT. However, patients also reported significantly less vitality, worse mental health as well as significantly more limitations due to physical and mental health 1 year after RT compared to the normal population. CONCLUSIONS: In this study, patients with PCa did not experience significant impairment in the QoL 1 year after RT compared to baseline. However, patients reported significantly worse mental health before, during and 1 year after RT compared to the normal population.

Long working hours and alcohol use: systematic review and meta-analysis of published studies and unpublished individual participant data.

OBJECTIVE: To quantify the association between long working hours and alcohol use. DESIGN: Systematic review and meta-analysis of published studies and unpublished individual participant data. DATA SOURCES: A systematic search of PubMed and Embase databases in April 2014 for published studies, supplemented with manual searches. Unpublished individual participant data were obtained from 27 additional studies. REVIEW METHODS: The search strategy was designed to retrieve cross sectional and prospective studies of the association between long working hours and alcohol use. Summary estimates were obtained with random effects meta-analysis. Sources of heterogeneity were examined with meta-regression. RESULTS: Cross sectional analysis was based on 61 studies representing 333,693 participants from 14 countries. Prospective analysis was based on 20 studies representing 100,602 participants from nine countries. The pooled maximum adjusted odds ratio for the association between long working hours and alcohol use was 1.11 (95% confidence interval 1.05 to 1.18) in the cross sectional analysis of published and unpublished data. Odds ratio of new onset risky alcohol use was 1.12 (1.04 to 1.20) in the analysis of prospective published and unpublished data. In the 18 studies with individual participant data it was possible to assess the European Union Working Time Directive, which recommends an upper limit of 48 hours a week. Odds ratios of new onset risky alcohol use for those working 49-54 hours and ≥ 55 hours a week were 1.13 (1.02 to 1.26; adjusted difference in incidence 0.8 percentage points) and 1.12 (1.01 to 1.25; adjusted difference in incidence 0.7 percentage points), respectively, compared with working standard 35-40 hours (incidence of new onset risky alcohol use 6.2%). There was no difference in these associations between men and women or by age or socioeconomic groups, geographical regions, sample type (population based v occupational cohort), prevalence of risky alcohol use in the cohort, or sample attrition rate. CONCLUSIONS: Individuals whose working hours exceed standard recommendations are more likely to increase their alcohol use to levels that pose a health risk.

A multi-wave study of organizational justice at work and long-term sickness absence among employees with depressive symptoms.

OBJECTIVES: Mental health problems are strong predictors of long-term sickness absence (LTSA). In this study, we investigated whether organizational justice at work - fairness in resolving conflicts and distributing work - prevents risk of LTSA among employees with depressive symptoms. METHODS: In a longitudinal study with five waves of data collection, we examined a cohort of 1034 employees with depressive symptoms. Depressive symptoms and organizational justice were assessed by self-administered questionnaires and information on LTSA was derived from a national register. Using Poisson regression analyses, we calculated rate ratios (RR) for the prospective association of organizational justice and change in organizational justice with time to onset of LTSA. All analyses were sex stratified. RESULTS: Among men, intermediate levels of organizational justice were statistically significantly associated with a decreased risk of subsequent LTSA after adjustment for covariates [RR 0.49, 95% confidence interval (95% CI) 0.26-0.91]. There was also a decreased risk for men with high levels of organizational justice although these estimates did not reach statistical significance after adjustment (RR 0.47, 95% CI 0.20-1.10). We found no such results for women. In both sexes, neither favorable nor adverse changes in organizational justice were statistically significantly associated with the risk of LTSA. CONCLUSIONS: This study shows that organizational justice may have a protective effect on the risk of LTSA among men with depressive symptoms. A protective effect of favorable changes in organizational justice was not found.

Development and evaluation of a crosswalk between the SF-36 physical functioning scale and Health Assessment Questionnaire disability index in rheumatoid arthritis.

BACKGROUND: The SF-36 physical functioning scale (PF-10) and the Health Assessment Questionnaire disability index (HAQ-DI) are the most frequently used instruments for measuring self-reported physical function in rheumatoid arthritis (RA). The objective of this study was to develop a crosswalk between scores on the PF-10 and HAQ-DI in RA. METHODS: Item response theory (IRT) methods were used to co-calibrate both scales using data from 1791 RA patients. The appropriateness of a Rasch-based crosswalk was evaluated by comparing it with crosswalks based on a two-parameter and a multi-dimensional IRT model. The accuracy of the final crosswalk was cross-validated using baseline (n = 532) and 6-month follow-up (n = 276) data from an independent cohort of early RA patients. RESULTS: The PF-10 and HAQ-DI adequately fit a unidimensional Rasch model. Both scales measured a wide range of functioning, although the HAQ-DI tended to better target lower levels of functioning. The Rasch-based crosswalk performed similarly to crosswalks based on the two-parameter and multidimensional IRT models. Agreement between predicted and observed scale scores in the cross-validation sample was acceptable for group-level comparisons. The longitudinal validity in discriminating between disease response states was similar between observed and predicted scores. CONCLUSION: The crosswalk developed in this study allows for converting scores from one scale to the other and can be used for group-level analyses in patients with RA.

Job strain and tobacco smoking: an individual-participant data meta-analysis of 166,130 adults in 15 European studies.

BACKGROUND: Tobacco smoking is a major contributor to the public health burden and healthcare costs worldwide, but the determinants of smoking behaviours are poorly understood. We conducted a large individual-participant meta-analysis to examine the extent to which work-related stress, operationalised as job strain, is associated with tobacco smoking in working adults. METHODOLOGY AND PRINCIPAL FINDINGS: We analysed cross-sectional data from 15 European studies comprising 166,130 participants. Longitudinal data from six studies were used. Job strain and smoking were self-reported. Smoking was harmonised into three categories never, ex- and current. We modelled the cross-sectional associations using logistic regression and the results pooled in random effects meta-analyses. Mixed effects logistic regression was used to examine longitudinal associations. Of the 166,130 participants, 17% reported job strain, 42% were never smokers, 33% ex-smokers and 25% current smokers. In the analyses of the cross-sectional data, current smokers had higher odds of job strain than never-smokers (age, sex and socioeconomic position-adjusted odds ratio: 1.11, 95% confidence interval: 1.03, 1.18). Current smokers with job strain smoked, on average, three cigarettes per week more than current smokers without job strain. In the analyses of longitudinal data (1 to 9 years of follow-up), there was no clear evidence for longitudinal associations between job strain and taking up or quitting smoking. CONCLUSIONS: Our findings show that smokers are slightly more likely than non-smokers to report work-related stress. In addition, smokers who reported work stress smoked, on average, slightly more cigarettes than stress-free smokers.

Work-related violence and incident use of psychotropics.

Although the mental health consequences of domestic violence are well documented, empirical evidence is scarce regarding the mental health effects of violence in the workplace. Most studies have used data from small occupation-specific samples, limiting their generalizability. This article examines whether direct exposure to work-related violence is associated with clinically pertinent mental health problems, measured by purchases of psychotropics (antidepressants, anxiolytics, hypnotics), in a cross-occupational sample of 15,246 Danish employees free from using psychotropics at baseline. Self-reported data on work-related violence were merged with other data on purchases of medications through a national registry to estimate cause-specific hazard ratios during 3.6 years (1,325 days) of follow-up in the years 1996-2008. Outcomes were examined as competing risks, and analyses were adjusted for gender, age, cohabitation, education, income, social support from colleagues, social support from supervisor, and influence and quantitative demands at work. Work-related violence was associated with purchasing antidepressants alone (hazard ratio = 1.38, 95% confidence interval: 1.09, 1.75) or in combination with anxiolytics (hazard ratio = 1.74, 95% confidence interval: 1.13, 2.70) but not with purchasing anxiolytics or hypnotics only. The frequency of violent episodes and risk of caseness were unrelated. Work-related violence is associated with increased risk of clinically pertinent mental health problems. Reducing levels of work-related violence may help to prevent mental disorders in the working population.

Health and role functioning: the use of focus groups in the development of an item bank.

BACKGROUND: Role functioning is an important part of health-related quality of life. However, assessment of role functioning is complicated by the wide definition of roles and by fluctuations in role participation across the life-span. The aim of this study is to explore variations in role functioning across the lifespan using qualitative approaches, to inform the development of a role functioning item bank and to pilot test sample items from the bank. METHODS: Eight focus groups were conducted with a convenience sample of 38 English-speaking adults recruited in Rhode Island. Participants were stratified by gender and four age groups. Focus groups were taped, transcribed, and analyzed for thematic content. RESULTS: Participants of all ages identified family roles as the most important. There was age variation in the importance of social life roles, with younger and older adults rating them as more important. Occupational roles were identified as important by younger and middle-aged participants. The potential of health problems to affect role participation was recognized. Participants found the sample items easy to understand, response options identical in meaning and preferred five response choices. CONCLUSIONS: Participants identified key aspects of role functioning and provided insights on their perception of the impact of health on their role participation. These results will inform item bank generation.

Development and preliminary testing of a computerized adaptive assessment of chronic pain.

UNLABELLED: The aim of this article is to report the development and preliminary testing of a prototype computerized adaptive test of chronic pain (CHRONIC PAIN-CAT) conducted in 2 stages: (1) evaluation of various item selection and stopping rules through real data-simulated administrations of CHRONIC PAIN-CAT; (2) a feasibility study of the actual prototype CHRONIC PAIN-CAT assessment system conducted in a pilot sample. Item calibrations developed from a US general population sample (N = 782) were used to program a pain severity and impact item bank (kappa = 45), and real data simulations were conducted to determine a CAT stopping rule. The CHRONIC PAIN-CAT was programmed on a tablet PC using QualityMetric's Dynamic Health Assessment (DYHNA) software and administered to a clinical sample of pain sufferers (n = 100). The CAT was completed in significantly less time than the static (full item bank) assessment (P < .001). On average, 5.6 items were dynamically administered by CAT to achieve a precise score. Scores estimated from the 2 assessments were highly correlated (r = .89), and both assessments discriminated across pain severity levels (P < .001, RV = .95). Patients' evaluations of the CHRONIC PAIN-CAT were favorable. PERSPECTIVE: This report demonstrates that the CHRONIC PAIN-CAT is feasible for administration in a clinic. The application has the potential to improve pain assessment and help clinicians manage chronic pain.

Evaluation of a computer-adaptive test for the assessment of depression (D-CAT) in clinical application.

In the past, a German Computerized Adaptive Test, based on Item Response Theory (IRT), was developed for purposes of assessing the construct depression [Computer-adaptive test for depression (D-CAT)]. This study aims at testing the feasibility and validity of the real computer-adaptive application.The D-CAT, supplied by a bank of 64 items, was administered on personal digital assistants (PDAs) to 423 consecutive patients suffering from psychosomatic and other medical conditions (78 with depression). Items were adaptively administered until a predetermined reliability (r > or = 0.90) was attained. For validation purposes, the Hospital Anxiety and Depression Scale (HADS), the Centre for Epidemiological Studies Depression (CES-D) scale, and the Beck Depression Inventory (BDI) were administered. Another sample of 114 patients was evaluated using standardized diagnostic interviews [Composite International Diagnostic Interview (CIDI)].The D-CAT was quickly completed (mean 74 seconds), well accepted by the patients and reliable after an average administration of only six items. In 95% of the cases, 10 items or less were needed for a reliable score estimate. Correlations between the D-CAT and the HADS, CES-D, and BDI ranged between r = 0.68 and r = 0.77. The D-CAT distinguished between diagnostic groups as well as established questionnaires do.The D-CAT proved an efficient, well accepted and reliable tool. Discriminative power was comparable to other depression measures, whereby the CAT is shorter and more precise. Item usage raises questions of balancing the item selection for content in the future.

Item response theory methods can improve the measurement of physical function by combining the modified health assessment questionnaire and the SF-36 physical function scale.

OBJECTIVE: To compare the measurement properties of the Modified Health Assessment Questionnaire [MHAQ], the SF-36((R)) Health Survey 10 item Physical Functioning scale [PF10], and scores from an item response theory (IRT) based scale combining the two measures. STUDY DESIGN: Rheumatoid arthritis (RA) patients (n = 339) enrolled in a multi-center, randomized, double-blind, placebo-controlled trial completed the MHAQ and the SF-36 pre- and post-treatment. Psychometric analyses used confirmatory factor analysis and IRT models. Analyses of variance were used to assess sensitivity to changes in disease severity (defined by the American College of Rheumatism (ACR)) using change scores in MHAQ, PF10, and IRT scales. Analyses of covariance were used to assess treatment responsiveness. RESULTS: For the entire score range, the 95% confidence interval around individual patient scores was smaller for the combined (total) IRT based scale than for other measures. The MHAQ and PF10 were about 70% and 50% as efficient as the total IRT score of physical functioning in discriminating among ACR groups, respectively. The MHAQ and PF10 were also less efficient than the total IRT score in discriminating among treatment groups. CONCLUSIONS: Combining scales from the two short forms yields a more powerful tool with greater sensitivity to treatment response.

Burnout among employees in human service work: design and baseline findings of the PUMA study.

AIM: To present the theoretical framework, design, methods, and baseline findings of the first Danish study on determinants and consequences of burnout, and the impact of workplace interventions in human service work organizations. METHOD: A 5-year prospective intervention study comprising 2,391 employees from different organizations in the human service sector: social security offices, psychiatric prison, institutions for severely disabled, hospitals, and homecare services. Data were collected at baseline and at two follow-ups. The authors developed a new burnout tool (the Copenhagen Burnout Inventory) covering work-related, client-related, and personal burnout. The study includes potential determinants of burnout (e.g. the psychosocial work environment, social relations outside work, lifestyle factors, and personality aspects) and consequences of burnout (e.g. poor health, low job satisfaction, turnover, and absenteeism). Here, the focus is on the description of the study population at baseline, including associations of work burnout with psychosocial work environment scales and absence. RESULTS: Response rate at baseline was 80.1%. Midwives and homecare workers had high levels on both work- and client-related burnout. Prison officers had the highest level on client-related burnout. Supervisors and office assistants had low levels on both scales. Work burnout showed the highest correlations with job satisfaction (r = -0.51), quantitative demands (r = 0.48), role-conflicts (r = 0.44), and emotional demands (r = 0.42). Sickness absence was 13.9 vs 6.0 days among participants in the highest and lowest work burnout quartile, respectively. CONCLUSION: The findings indicate that study design and methods are adequate for the upcoming prospective analyses of aetiology and consequences of burnout and of the impact of workplace interventions.

The development of the EORTC QLQ-C15-PAL: a shortened questionnaire for cancer patients in palliative care.

This study aimed at developing a shortened version of the EORTC QLQ-C30, one of the most widely used health-related quality of life questionnaires in oncology, for palliative care research. The study included interviews with 41 patients and 66 health care professionals in palliative care to determine the appropriateness, relevance and importance of the various domains of the QLQ-C30. Item response theory methods were used to shorten scales. Patients and health care professionals rated pain, physical function, emotional function, fatigue, global health status/quality of life, nausea/vomiting, appetite, dyspnoea, constipation, and sleep as most important. Therefore, these scales/items were retained in the questionnaire. Four scales were shortened without reducing measurement precision. Important dimensions not covered by the questionnaire were identified. The resulting 15-item EORTC QLQ-C15-PAL is a 'core questionnaire' for palliative care. Depending on the research questions, it may be supplemented by additional items, modules or questionnaires.

The Short-Form Headache Impact Test (HIT-6) was psychometrically equivalent in nine languages.

BACKGROUND AND OBJECTIVE: This study examined the psychometric properties and equivalence of the six-item Headache Impact Test (HIT-6) across 11 languages in 14 countries. METHODS: A multicenter, international cross-sectional study conducted in a primary care setting. Data obtained from 1,171 adults from 14 countries who consulted their primary care physician for headache completed the HIT-6 questionnaire and a headache survey were included in this analysis. Item-level statistics (e.g., range of response choices used by participants), item-scale statistics (e.g., item-total correlations), scale level statistics (e.g., internal consistency reliability), and tests of differential item functioning were conducted to examine the psychometric properties of all HIT-6 translations and their comparability across translations. RESULTS: Across languages, missing data were low, item-scale correlations were high, reliability was adequate, and item-level statistics were generally comparable. We found only minor differential item functioning, suggesting that the HIT-6 translations are equivalent to the U.S. English form. CONCLUSIONS: Psychometric analyses indicate that most HIT-6 translations (Canadian English, French, Greek, Hungarian, UK English, Hebrew, Portuguese, German, Spanish, and Dutch) are comparable to U.S. English. Improvements may be needed in the Finnish and Slovakian translations and the appropriateness of using the HIT-6 in South Africa should be explored further.

Applications of computerized adaptive testing (CAT) to the assessment of headache impact.

OBJECTIVE: To evaluate the feasibility of computerized adaptive testing (CAT) and the reliability and validity of CAT-based estimates of headache impact scores in comparison with 'static' surveys. METHODS: Responses to the 54-item Headache Impact Test (HIT) were re-analyzed for recent headache sufferers (n = 1016) who completed telephone interviews during the National Survey of Headache Impact (NSHI). Item response theory (IRT) calibrations and the computerized dynamic health assessment (DYNHA) software were used to simulate CAT assessments by selecting the most informative items for each person and estimating impact scores according to pre-set precision standards (CAT-HIT). Results were compared with IRT estimates based on all items (total-HIT), computerized 6-item dynamic estimates (CAT-HIT-6), and a developmental version of a 'static' 6-item form (HIT-6-D). Analyses focused on: respondent burden (survey length and administration time), score distributions ('ceiling' and 'floor' effects), reliability and standard errors, and clinical validity (diagnosis, level of severity). A random sample (n = 245) was re-assessed to test responsiveness. A second study (n = 1103) compared actual CAT surveys and an improved 'static' HIT-6 among current headache sufferers sampled on the Internet. Respondents completed measures from the first study and the generic SF-8 Health Survey; some (n = 540) were re-tested on the Internet after 2 weeks. RESULTS: In the first study, simulated CAT-HIT and total-HIT scores were highly correlated (r = 0.92) without 'ceiling' or 'floor' effects and with a substantial reduction (90.8%) in respondent burden. Six of the 54 items accounted for the great majority of item administrations (3603/5028, 77.6%). CAT-HIT reliability estimates were very high (0.975-0.992) in the range where 95% of respondents scored, and relative validity (RV) coefficients were high for diagnosis (RV = 0.87) and severity (RV = 0.89); patient-level classifications were accurate 91.3% for a diagnosis of migraine. For all three criteria of change, CAT-HIT scores were more responsive than all other measures. In the second study, estimates of respondent burden, item usage, reliability and clinical validity were replicated. The test-retest reliability of CAT-HIT was 0.79 and alternate forms coefficients ranged from 0.85 to 0.91. All correlations with the generic SF-8 were negative. CONCLUSIONS: CAT-based administrations of headache impact items achieved very large reductions in respondent burden without compromising validity for purposes of patient screening or monitoring changes in headache impact over time. IRT models and CAT-based dynamic health assessments warrant testing among patients with other conditions.