What is the evidence for the performance of generic preference-based measures? A systematic overview of reviews

Objective

To assess the evidence on the validity and responsiveness of five commonly used preference-based instruments, the EQ-5D, SF-6D, HUI3, 15D and AQoL, by undertaking a review of reviews.

Methods

Four databases were investigated using a strategy refined through a highly sensitive filter for systematic reviews. References were screened and a search for grey literature was performed. Identified citations were scrutinized against pre-defined eligibility criteria and data were extracted using a customized extraction template. Evidence on known group validity, convergent validity and responsiveness was extracted and reviewed by narrative synthesis. Quality of the included reviews was assessed using a modified version of the AMSTAR checklist.

Results

Thirty reviews were included, sixteen of which were of excellent or good quality. The body of evidence, covering more than 180 studies, was heavily skewed towards EQ-5D, with significantly fewer studies investigating HUI3 and SF-6D, and very few the 15D and AQoL. There was also lack of head-to-head comparisons between GPBMs and the tests reported by the reviews were often weak. Where there was evidence, EQ-5D, SF-6D, HUI3, 15D and AQoL seemed generally valid and responsive instruments, although not for all conditions. Evidence was not consistently reported across reviews.

Conclusions

Although generally valid, EQ-5D, SF-6D and HUI3 suffer from some problems and perform inconsistently in some populations. The lack of head-to-head comparisons and the poor reporting impedes the comparative assessment of the performance of GPBMs. This highlights the need for large comparative studies designed to test instruments’ performance.

     

Translation and validation of non-English versions of the Ankylosing Spondylitis Quality of Life (ASQOL) questionnaire

Background

The EQ-5D is a reliable tool for measuring Health-Related Quality of Life (HRQoL). However, concern has been expressed that it may ignore elements of HRQoL, particularly cognition. In response to this concern, the EQ-5D has been extended with a cognitive dimension (EQ-5D+C). The aim of this study was to compare the performance of the EQ-5D and the EQ-5D+C in elderly patients with cognitive impairments by assessing their construct validity and responsiveness.

Methods

Data from the MEDICIE study (n = 196) were used, in which all questionnaires were rated by proxies.

Results

Regarding construct validity, we found similar correlations between the EQ-5D and the Mini Mental State Examination (MMSE) and between the EQ-5D+C and the MMSE. Furthermore, both the EQ-5D and the EQ-5D+C were responsive to changes in the MMSE, with the EQ-5D performing slightly better.

Conclusion

We conclude that the EQ-5D performs well for evaluating HRQoL in a population with cognitive impairments. Based on the results of this explorative study, it does not seem necessary to adjust the current classification system by adding a cognitive dimension. However, in order to compare both instruments regarding utility values, it is necessary to develop a new scoring algorithm for the EQ-5D+C by conducting a general population study. Considering the explorative nature of this study, it is recommended that more aspects of the validity of both the EQ-5D and the EQ-5D+C are explored in patients with cognitive impairments using a more tailored study design.     

Validity of the Thai EQ-5D in an occupational population in Thailand

Purpose

To assess the construct validity of the Thai EuroQoL (EQ-5D) among an occupational population in Thailand.

Methods

Data were derived from a large cohort study among employees of the Electricity Generating Authority of Thailand. In 2008 and 2009, 4,850 participants completed the Thai EQ-5D and Short-Form 36 version 2 (SF-36v2). Thai preferences weights were used to convert EQ-5D health states into EQ-5D index scores. Construct validity of the Thai EQ-5D was examined by specifying and testing hypotheses about the relationships between the EQ-5D, SF-36v2, and participants’ demographic and medical characteristics.

Results

Construct validity of the Thai EQ-5D was supported by expected relationships with SF-36v2 scale and summary scores. For example, SF-36v2 scores on the mental health scale were much lower for participants who reported having problems on the EQ-5D anxiety/depression dimension compared to those reporting no problems (mean norm-based SF-36v2 scores: 52.9 vs. 41.8, p < 0.001). Additionally, reporting a problem in a given EQ-5D dimension was generally associated with lower SF-36v2 summary scores. The EQ-5D index score distinguished between groups of participants in the expected manner, on the basis of sex, age, education and self-reported health, thus providing evidence of known-groups validity.

Conclusion

The study demonstrated good construct validity of the Thai EQ-5D in a large occupational population in Thailand.     

24th Annual Conference of the International Society for Quality of Life Research

Purpose

Generic preference-based quality of life (PbQoL) measures are sometimes criticized for being insensitive or failing to capture important aspects of quality of life (QoL) in specific populations. The objective of this study was to systematically review and assess the construct validity and responsiveness of PbQoL measures in Parkinson’s.

Methods

Ten databases were systematically searched up to July 2015. Studies were included if a PbQoL instrument along with a common Parkinson’s clinical or QoL measure was used, and the utility values were reported. The PbQoL instruments were assessed for construct validity (discriminant and convergent validity) and responsiveness.

Results

Twenty-three of 2758 studies were included, of which the majority evidence was for EQ-5D. Overall good evidence of discriminant validity was demonstrated in the Health Utility Index (HUI)-3, EQ-5D-5L, EQ-5D-3L, 15D, HUI-2, and Disability and Distress Index (DDI). Nevertheless, HUI-2 and EQ-5D-3L were shown to be less sensitive among patients with mild Parkinson’s. Moderate to strong correlations were shown between the PbQoL measures (EQ-5D-3L, EQ-5D-5L, 15D, DDI, and HUI-II) and Parkinson’s-specific measures. Twelve studies provided evidence for the assessment of responsiveness of EQ-5D-3L and one study for 15D, among which six studies reached inconsistent results between EQ-5D-3L and the Parkinson’s-specific measures in measuring the change overtime.

Conclusions

The construct validity of the PbQoL measures was generally good, but there are concerns regarding their responsiveness to change. In Parkinson’s, the inclusion of a Parkinson’s-specific QoL measure or a generic but broader scoped mental and well-being focused measure to incorporate aspects not included in the common PbQoL measures is recommended.

     

Evidence on the longitudinal construct validity of major generic and utility measures of health-related quality of life in teens with depression

Purpose

To examine the longitudinal construct validity in the assessment of changes in depressive symptoms of widely used utility and generic HRQL instruments in teens.

Methods

392 teens enrolled in the study and completed HRQL and diagnostic measures as part of the baseline interview. HRQL measures included EuroQol (EQ-5D-3L), Health Utilities Index Mark 2 (HUI2) and Mark 3 (HUI3), Quality of Well-Being Scale (QWB), Pediatric Quality of Life Inventory (PEDS-QL), RAND-36 (SF-6D), and Quality of Life in Depression Scale (QLDS). Youth completed follow-up interviews 12 weeks after baseline. Sixteen youth (4.1%) were lost to follow-up. We examined correlations between changes in HRQL instruments and the Children’s Depression Rating Scale-Revised (CDRS-R) and assessed clinically meaningful change in multi-attribute utility HRQL measures using mean change (MC) and standardized response mean (SRM) among youth showing at least moderate (20%) improvement in depression symptomology.

Results

Spearman’s correlation coefficients demonstrated moderate correlation between changes in CDRS-R and the HUI2 (r?=?0.38), HUI3 (r?=?0.42), EQ-5D-3L (r?=?0.36), SF-6D (r?=?0.39), and PEDS-QL (r?=?0.39) and strong correlation between changes in CDRS-R and QWB (r?=?0.52) and QLDS (r?=???0.71). Effect size results are also reported. Among multi-attribute utility measures, all showed clinically meaningful improvements in the sample of youth with depression improvement (HUI2, MC?=?0.20, SRM?=?0.97; HUI3, MC?=?0.32, SRM?=?1.17; EQ-5D-3L, MC?=?0.08, SRM?=?0.51; QWB, MC?=?0.11, SRM?=?0.86; and SF-6D, MC?=?0.12, SRM?=?1.02).

Conclusions

Findings support the longitudinal construct validity of included HRQL instruments for the assessment of change in depression outcomes in teens. Results of this study can help inform researchers about viable instruments to include in economic evaluations for this population.

     

Comparison of three societally derived health-state classification values among older African Americans with depressive symptoms

Purpose

To compare societal values across three health-state classification systems in older African Americans with depression and to describe the association of these instruments to depression severity.

Methods

We summarized baseline values for EQ-5D (US weights) and HUI2/3 (Canadian weights) and their subscales for 118 older African American participants enrolled in a randomized depression treatment trial and calculated correlations between the different instruments. We evaluated ceiling and floor effects for each instrument by comparing the proportion at the highest and lowest possible score for each tool. Also, utility scores were assessed by level of depression severity (mild, moderate, moderate severe, severe) scores as measured by the Patient Health Questionnaire (PHQ-9).

Results

Mean utility values were 0.58 (SD = 0.21) for EQ-5D, 0.52 (SD = 0.21) for HUI2, and 0.36 (SD = 0.31) for HUI3. For the EQ-5D, 72 % of participants reported having some problems on the anxiety/depression domain. On the emotion domain for the HUI2, 23 % reported the highest level of impairment compared to only 3 % on the HUI3. No participant scored at the floor for the EQ-5D, HUI2, or HUI3 index; one participant scored at the ceiling value on the HUI3 index. Correlations ranged from 0.63 to 0.82 (all of which were significant at an alpha level of 0.05). In general, utility scores trended inversely with depression level.

Conclusion

Small differences in the three preference-weighted health-state classification systems were evident for this sample of older African Americans with depressive symptoms, with HUI scores lower than EQ-5D. For this sample, utility scores were lower (i.e., poorer) than the general United States population with depression on each utility measure.     

An evaluation of patient-reported outcome measures in lower limb reconstruction surgery

Purpose

To assess the measurement properties (acceptability, validity, reliability and responsiveness), of the MOS 36-Item Short-Form Health Survey (SF-36), the EQ-5D, the Short-Form McGill Pain Questionnaire (SF-MPQ) and the Musculoskeletal Functional Assessment Instrument (MFA), in patients who have undergone limb reconstruction surgery (LRS).

Methods

Four instruments measuring patient-reported outcome were completed at baseline and 12?months from surgery.

Results

101 LRS patients were recruited with 95 responding at baseline and 71 at a 12-month follow-up. Response rates at baseline were over 94%. In three instruments, there was evidence of floor or ceiling effect, the exception being the EQ-5D. Cronbach??s ?? statistics of internal consistency reliability were acceptable at ??0.80 for all dimensions of the MFA, the SF-MPQ PRI(S) and seven of the SF-36 dimensions. When comparing mean changes in scores between baseline and 12?months, the most responsive measure was the SF-36 with an average Standardised Response Mean of 0.48 for those who reported their health as better. Statistically significant differences were observed between the health change groups (??worse??, ??better?? and ??same??) for four dimensions of the SF-36, the two summary scores and the SF-6D.

Conclusions

Variation and poor performance of some of the instruments resulted in a recommendation of using the SF-36 and the SF-6D for LRS patients.     

Development and validation of a mental health subscale from the Quality of Well-Being Self-Administered

Purpose

The purpose of this study was to create and validate a mental health subscale for the Quality of Well-Being Self-Administered (QWB-SA).

Methods

The QWB-SA and other measures such as the Profile of Mood States (POMS), Medical Outcomes Study 36 Item Short Form (SF-36), EuroQOL 5D (EQ-5D), and Health Utilities Index Mark 2 (HUI) were administered to three samples: a general population (N = 3,844), a non-psychiatric medical population (N = 535), and a psychiatric population (N = 915). Independent expert ratings of which items represented the construct of mental health were used along with psychometric methods to develop and validate a 10-item QWB-SA mental health scale.

Results

The mental health scale demonstrated high internal consistency (Cronbach’s alpha = 0.827–0.842) and strong correlations with other measures of mental health, such as the POMS (r = ?0.77), mental health scale from the SF-36 (r = 0.72), EQ-5D mood item (r = 0.61), and HUI Emotion Scale (r = 0.59). It was not highly correlated with measures of physical health. Among the psychiatric population, the new mental health scale was moderately correlated with indicators of psychiatric problem severity.

Conclusions

It is now possible to report outcomes and relationships with mental health in studies that use the QWB-SA. This new mental health subscale can also be used with the large volume of previously collected data using the QWB-SA to examine the impact of illnesses and interventions on mental health-related quality of life.     

Comparative performance of the EQ-5D-5L and SF-6D index scores in adults with type 2 diabetes

Purpose

To explore the comparative performance including discriminative and longitudinal validity of EQ-5D-5L and SF-6D index scores in adults with type 2 diabetes.

Methods

Data from an on-going cohort study of adults with type 2 diabetes in Alberta, Canada, were used. Known-groups approach was used to examine discriminative validity. Correlation and agreement indices and scatter and Bland–Altman plots were used to examine the relationship between the two measures. Longitudinal validity was explored using Wilcoxon signed-rank test, effect size, and standardized response mean.

Results

In 1832 participants at baseline (age 64.3, standard deviation 10.6 years; 45% female), median EQ-5D-5L score was 0.85 [interquartile range (IQR) 0.17], and floor and ceiling effects of 0.1 and 16.1%, respectively; median SF-6D score was 0.72 (IQR 0.24), and floor and ceiling effects of 0.1 and 3.2%, respectively. EQ-5D-5L and SF-6D index scores were significantly correlated with an overall Spearman correlation coefficient of 0.73, and an ICC of 0.62 (95% CI 0.42–0.74). Both EQ-5D-5L and SF-6D scores demonstrated statistically significant differences in self-reported chronic conditions, depressive symptoms, and diabetes-related distress, and were able to detect changes in depressive symptoms and diabetes distress across all change groups.

Conclusions

Both EQ-5D-5L and SF-6D index scores provide valid measurement in this patient population. Considerable overlap between the measures means it is not necessary to include both in surveys, however, the advantages and disadvantages of each should be considered.

     

Validity, reliability and responsiveness of the EQ-5D in German stroke patients undergoing rehabilitation

Purpose

To analyse the psychometric properties of the EQ-5D in German stroke survivors undergoing neurological rehabilitation.

Methods

The EQ-5D, the Hospital Anxiety and Depression Scale (HADS) and the Stroke Impact Scale (SIS) were completed before (210 subjects) and after (183 subjects) a patient education programme in seven rehabilitation clinics in Bavaria, Germany. A postal follow-up was conducted after 6?months. Acceptance, validity, reliability and responsiveness of the EQ-5D were tested. The SIS subscales were used as external anchors to classify the patients into change groups between the measurements.

Results

The proportion of missing answers ranged from 4.7 to 8.6%. Between 16 and 19% reported no problems in any EQ-5D dimension. At baseline, correlations between EQ-5D index and the SIS subscales ranged from 0.15 (communication) to 0.60 (mobility). Correlations with the EQ VAS were slightly smaller. All scores were reliable in test?Cretest with intraclass correlations ranging from 0.67 to 0.81. EQ-5D index and EQ VAS were consistently responsive only to improvements in health, showing small- to medium effect sizes (0.27?C0.42).

Conclusions

The EQ-5D has shown reasonable validity, reliability and, more limited, responsiveness in stroke patients with mild to moderate limitations of functional status, allowing it to be used in clinical trials in rehabilitation.     

Choosing between measures: comparison of EQ-5D,HUI2 and HUI3 in persons with hearing complaints

Objectives To generate insight into the differences between utility measures EuroQol 5D (EQ-5D), Health Utilities Index Mark II (HUI2) and Mark III (HUI3) and their impact on the incremental cost-effectiveness ratio (ICER) for hearing aid fitting Methods Persons with hearing complaints completed EQ-5D, HUI2 and HUI3 at baseline and, when applicable, after hearing aid fitting. Practicality, construct validity, agreement, responsiveness and impact on the ICER were examined. Results All measures had high completion rates. HUI3 was capable of discriminating between clinically distinctive groups. Utility scores (n = 315) for EQ-5D UK and Dutch tariff (0.83; 0.86), HUI2 (0.77) and HUI3 (0.61) were significantly different, agreement was low to moderate. Change after hearing aid fitting (n = 70) for HUI2 (0.07) and HUI3 (0.12) was statistically significant, unlike the EQ-5D UK (0.01) and Dutch (0.00) tariff. ICERs varied from €647,209/QALY for the EQ-5D Dutch tariff to €15,811/QALY for HUI3. Conclusion Utility scores, utility gain and ICERs heavily depend on the measure that is used to elicit them. This study indicates HUI3 as the instrument of first choice when measuring utility in a population with hearing complaints, but emphasizes the importance of a clear notion of what constitutes utility with regard to economic analyses.     

Psychometric properties of the EuroQol Five Dimensional Questionnaire (EQ-5D-3L) in caregivers of autistic children

Purpose

This study aimed to ascertain the psychometric properties of EuroQol Five Dimensional Questionnaire (EQ-5D-3L) in primary caregivers of children with autism. The convergent validity, discriminant validity, known-groups validity, internal consistency reliability, and floor and ceiling effects of EQ-5D-3L were analyzed.

Methods

A cross-sectional design was used for study purposes. Through an online survey, relevant study information was collected from 316 primary caregivers of children with autism. Study participants were from families of children with autism living in the United States who were registered with the Interactive Autism Network. Convergent validity of the EQ-5D-3L was assessed through its correlation with other measures of similar constructs. Discriminant validity was assessed by observing the correlation of EQ-5D-3L domains with theoretically unrelated constructs. Known-groups validity was tested by comparing EQ-5D-3L index and visual analog scale (VAS) scores across levels of autism severity among the care recipients. Internal consistency reliability of EQ-5D-3L was tested. Lastly, floor and ceiling effects of EQ-5D-3L were assessed.

Results

More than 60 % of participants reported problems of ‘anxiety/depression.’ Convergent and discriminant validity of the EQ-5D-3L was good. Significant correlation (convergent validity) was observed among EQ-5D-3L index and VAS and (SF-12v2) physical component summary and mental component summary scores. Caregivers’ EQ-5D-3L index and VAS scores varied by levels of autism severity among care recipients, providing evidence of known-groups validity. Reliability assessed through Cronbach’s alpha was less than satisfactory; however, corrected item-total correlations were adequate.

Conclusions

The EQ-5D-3L is a psychometrically sound tool to elicit health state preferences among caregivers of children with autism.     

Exploring psychometric properties of the SF-6D,a preference-based health-related quality of life measure,in the context of spinal cord injury

Purpose

The validity of the SF-6D, a preference-based measure of health-related quality of life, is not well explored in the context of spinal cord injury (SCI). The aim of this analysis was to assess appropriate measurement properties of the SF-6D in a sample of individuals living with SCI.

Methods

Longitudinal data from the Rick Hansen Spinal Cord Injury Registry were used. Responses to the 36-item short-form health survey were transformed into SF-6D utility scores. We investigated practicality, floor and ceiling effects, and responsiveness to change. Responsiveness to change was explored using three different anchors that reflected changes in self-reported health, functional independence, and life satisfaction. Discriminative validity was assessed by ten a priori defined hypotheses, with a distinction made between ‘strong’ and ‘weak’ hypotheses.

Results

Three hundred and fifty-eight individuals with SCI were included in this analysis. Practicality was deemed acceptable based on a completion rate of 94 %. The SF-6D showed low responsiveness to detect important health changes over time, and differences in responsiveness were found between individuals with paraplegia and tetraplegia. All five strong hypotheses and three weak hypotheses were confirmed.

Conclusion

The SF-6D demonstrated good practicality and discriminative validity in this sample. The failure to detect self-reported and clinically important health changes requires further consideration. Comparative performance of the SF-6D (i.e., how the SF-6D performs against other preference-based measures) is unknown in the SCI context and requires further research.     

Estimating utilities for chronic kidney disease, using SF-36 and SF-12-based measures: challenges in a population of veterans with diabetes

Purpose

Using transformations of existing quality-of-life data to estimate utilities has the potential to efficiently provide investigators with utility information. We used within-method and across-method comparisons and estimated disutilities associated with increasing chronic kidney disease (CKD) severity.

Methods

In an observational cohort of veterans with diabetes (DM) and pre-existing SF-36/SF-12 responses, we used six transformation methods (SF-12 to EQ-5D, SF-36 to HUI2, SF-12 to SF-6D, SF-36 to SF-6D, SF-36 to SF-6D (Bayesian method), and SF-12 to VR-6D) to estimate unadjusted utilities. CKD severity was staged using glomerular filtration rate estimated from serum creatinines, with the modification of diet in renal disease formula. We then used multivariate regression to estimate disutilities specifically associated with CKD severity stage.

Results

Of 67,963 patients, 22,273 patients had recent-onset DM and 45,690 patients had prevalent DM. For the recent-onset group, the adjusted disutility associated with CKD derived from the six transformation methods ranged from 0.0029 to 0.0045 for stage 2; ?0.004 to ?0.0009 for early stage 3; ?0.017 to ?0.010 for late stage 3; ?0.023 to ?0.012 for stage 4; ?0.078 to ?0.033 for stage 5; and ?0.012 to ?0.001 for ESRD/dialysis.

Conclusion

Disutility did not increase monotonically as CKD severity increased. Differences in disutilities estimated using the six different methods were found. Both findings have implications for using such estimates in economic analyses.     

Interpersonal discrimination and health-related quality of life among black and white men and women in the United States

Objective

We assessed associations between discrimination and health-related quality of life among black and white men and women in the United States.

Methods

We examined data from the National Health Measurement Study, a nationally representative sample of 3,648 adults aged 35–89 in the non-institutionalized US population. These data include self-reported lifetime and everyday discrimination as well as several health utility indexes (EQ-5D, HUI3, and SF-6D). Multiple regression was used to compute mean health utility scores adjusted for age, income, education, and chronic diseases for each race-by-gender subgroup.

Results

Black men and women reported more discrimination compared to white men and women. Health utility tended to be worse as reported discrimination increased. With a few exceptions, differences between mean health utility scores in the lowest and highest discrimination groups exceeded the 0.03 difference generally considered to be a clinically significant difference.

Conclusions

Persons who experienced discrimination tended to score lower on health utility measures. The study also revealed a complex relationship between experiences of discrimination and race and gender. Because of these differential social and demographic relationships caution is urged when interpreting self-rated health measures in research, clinical, and policy settings.     

Erratum to: Interpersonal discrimination and health-related quality of life among black and white men and women in the United States

Objective

We assessed associations between discrimination and health-related quality of life among black and white men and women in the United States.

Methods

We examined data from the National Health Measurement Study, a nationally representative sample of 3,648 adults aged 35–89 in the non-institutionalized US population. These data include self-reported lifetime and everyday discrimination as well as several health utility indexes (EQ-5D, HUI3, and SF-6D). Multiple regression was used to compute mean health utility scores adjusted for age, income, education, and chronic diseases for each race-by-gender subgroup.

Results

Black men and women reported more discrimination than white men and women. Health utility tended to be worse as reported discrimination increased. With a few exceptions, differences between mean health utility scores in the lowest and highest discrimination groups exceeded the 0.03 difference generally considered to be a clinically significant difference.

Conclusions

Persons who experienced discrimination tended to score lower on health utility measures. The study also revealed a complex relationship between experiences of discrimination and race and gender. Because of these differential social and demographic relationships caution is urged when interpreting self-rated health measures in research, clinical, and policy settings.     

Probabilistic mapping of the health status measure SF-12 onto the health utility measure EQ-5D using the US-population-based scoring models

Purpose

Probabilistic mapping of the health status instrument SF-12 onto the health utility instrument EuroQol—5 dimensions (EQ-5D)-3L using the UK-population-based scoring model showed encouraging results as compared to other mapping methods, although its predictive performance using the US-population-based EQ-5D scoring models has not been investigated. In addition, a new and improved US-population-based EQ-5D scoring method has recently been developed and suggested for use in applications that required US societal health state values. In this study, we assessed predictive performance of the probabilistic mapping approach using the US-population-based scoring models on EQ-5D utility scores based on SF-12 responses and compared the results with those of other mapping methods.

Methods

Using a sample of 19,678 adults from the 2003 Medical Expenditure Panel Survey, we evaluated the predictive performance of probabilistic mapping using Bayesian networks, response mapping using multinomial logistic regression, ordinary least squares, and censored least absolute deviations models by implementing a fivefold cross-validation method. The EQ-5D utility scores were generated using two US-population-based models: D1 and MM-OC.

Results

Overall, the probabilistic mapping approach using Bayesian networks consistently outperformed other mapping methods with mean squared errors (MSE) of 0.007 and 0.007, mean absolute errors (MAE) of 0.057 and 0.039, and overall R ² of 0.773 and 0.770 for the US-population-based EQ-5D scoring D1 and MM-OC models, respectively.

Conclusion

The probabilistic mapping approach can be useful to estimate EQ-5D utility scores from SF-12 responses with better predictive measures in terms of MSE, MAE, and R ² than other common mapping methods.     

The effect of weight loss on changes in health-related quality of life among overweight and obese women with urinary incontinence

Objective

To estimate the effect of change in weight and change in urinary incontinence (UI) frequency on changes in preference-based measures of health-related quality of life (HRQL) among overweight and obese women with UI participating in a weight loss trial.

Methods

We conducted a longitudinal cohort analysis of 338 overweight and obese women with UI enrolled in a randomized clinical trial comparing a behavioral weight loss intervention to an educational control condition. At baseline, 6, and 18?months, health utilities were estimated using the Health Utilities Index Mark 3 (HUI3), a transformation of the SF-36 to the preference-based SF-6D, and the estimated Quality of Well-Being (eQWB) score (a summary calculated from the SF-36 physical functioning, mental health, bodily pain, general health perceptions, and role limitations?Cphysical subscale scores). Potential predictors of changes in these outcomes were examined using generalized estimating equations.

Results

In adjusted multivariable models, weight loss was associated with improvement in HUI3, SF-6D, and eQWB at 6 and 18?months (P?<?0.05). Increases in physical activity also were independently associated with improvement in HUI3 (P?=?0.01) and SF-6D (P?=?0.006) scores at 18?months. In contrast, reduction in UI frequency did not predict improvements in HRQL at 6 or 18?months.

Conclusion

Weight loss and increased physical activity, but not reduction in UI frequency, were strongly associated with improvements in health utilities measured by the HUI3, SF-6D, and eQWB. These findings provide important information that can be used to inform cost?Cutility analyses of weight loss interventions.