Development and refinement of the WAItE: a new obesity-specific quality of life measure for adolescents

A scoping review to create a framework for the steps in developing condition-specific preference-based instruments de novo or from an existing non-preference-based instrument: use of item response theory or Rasch analysis

BACKGROUND

There is no widely accepted framework to guide the development of condition-specific preference-based instruments (CSPBIs) that includes both de novo and from existing non-preference-based instruments. The purpose of this study was to address this gap by reviewing the published literature on CSPBIs, with particular attention to the application of item response theory (IRT) and Rasch analysis in their development.

METHODS

A scoping review of the literature covering the concepts of all phases of CSPBI development and evaluation was performed from MEDLINE, Embase, PsychInfo, CINAHL, and the Cochrane Library, from inception to December 30, 2022.

RESULTS

The titles and abstracts of 1,967 unique references were reviewed. After retrieving and reviewing 154 full-text articles, data were extracted from 109 articles, representing 41 CSPBIs covering 21 diseases or conditions. The development of CSPBIs was conceptualized as a 15-step framework, covering four phases: 1) develop initial questionnaire items (when no suitable non-preference-based instrument exists), 2) establish the dimensional structure, 3) reduce items per dimension, 4) value and model health state utilities. Thirty-nine instruments used a type of Rasch model and two instruments used IRT models in phase 3.

CONCLUSION

We present an expanded framework that outlines the development of CSPBIs, both from existing non-preference-based instruments and de novo when no suitable non-preference-based instrument exists, using IRT and Rasch analysis. For items that fit the Rasch model, developers selected one item per dimension and explored item response level reduction. This framework will guide researchers who are developing or assessing CSPBIs.

Valuing selected WAItE health states using the Time Trade-Off methodology: findings from an online interviewer-assisted remote survey

PURPOSE

The Weight-Specific Adolescent Instrument for Economic Evaluation (WAItE) is a physical weight-specific patient reported outcome measure for use in adolescence. The purpose of this study was to use the Time Trade-Off (TTO) methodology, administered using an online interviewer-assisted remote survey, to obtain utility values for several health states from the WAItE descriptive system from a sample of the UK adult general population.

METHODS

The adult sample was gathered using a market research company and a sample of local residents. All participants completed the same interviewer-assisted remote survey, which included rating WAItE states of varying impairment using the TTO.

RESULTS

42 adults completed the survey. Utility values were gathered for four health states, ranging from low impairment to the most severe health from the WAItE descriptive system (the Pits state). Consistent orderings of the WAItE health states were observed; the health state with the lowest level of impairment was valued highest and the Pits state was valued lowest. Several respondents (n = 7, 17%) considered the Pits state to be worse than death; however, the mean value of this health state was 0.23.

CONCLUSIONS

The utility value of the Pits state relative to death generated from this study will be used to anchor latent values for WAItE health states generated from a Discrete Choice Experiment onto the 0 = death, 1 = full health Quality Adjusted Life Year (QALY) scale as part of a valuation study for the WAItE in the UK population. This study also provides further evidence that interviewer-assisted digital studies are feasible for collecting TTO data.

Investigating the quality of life for children with autism spectrum disorder scale using Rasch methodology

Our purpose in this study was to provide additional psychometric evidence of the Quality of Life for Children with Autism Spectrum Disorder (QOLASD-C) scale. We used Rasch modeling to investigate the QOLASD-C functioning, the characteristics of the items comprising the scale, and the item functioning across subgroups of children with ASD based on gender and race/ethnicity. Results showed that QOLASD-C was unidimensional, met the local independence assumption, and measured quality of life (QOL). The items showed excellent fit to the model and good discriminating ability between low and high QOL. Most items showed a moderate difficulty level. No differential item functioning was observed based on children's gender and race/ethnicity. Implications for research and practice are discussed.

Developing the Breast Utility Instrument to Measure Health-Related Quality-of-Life Preferences in Patients with Breast Cancer: Selecting the Item for Each Dimension

Introduction. Generic preference-based instruments inadequately measure breast cancer (BrC) health-related quality-of-life preferences given advances in therapy. Our overall purpose is to develop the Breast Utility Instrument (BUI), a BrC-specific preference-based instrument. This study describes the selection of the BUI items. Methods. A total of 408 patients from diverse BrC health states completed the EORTC QLQ-C30 and BR45 (breast module). For each of 10 dimensions previously assessed with confirmatory factor analysis, we evaluated data fit to the Rasch model based on global model and item fit, including threshold ordering, item residuals, infit and outfit, differential item functioning (age), and unidimensionality. Misfitting items were removed iteratively, and the model fit was reassessed. From items fitting the Rasch model, we selected 1 item per dimension based on high patient- and clinician-rated item importance, breadth of item thresholds, and clinical relevance. Results. Global model fit was good in 7 and borderline in 3 dimensions. Separation index was acceptable in 4 dimensions. Item selection criteria were maximized for the following items: 1) physical functioning (trouble taking a long walk), 2) emotional functioning (worry), 3) social functioning (interfering with social activities), 4) pain (having pain), 5) fatigue (tired), 6) body image (dissatisfied with your body), 7) systemic therapy side effects (hair loss), 8) sexual functioning (interest in sex), 9) breast symptoms (oversensitive breast), and 10) endocrine therapy symptoms (problems with your joints). Conclusions. We propose 10 items for the BUI. Our next steps include assessing the measurement properties prior to eliciting preference weights of the BUI.

Highlights

A previous confirmatory factor analysis established 10 dimensions of the European Organisation for Research and Treatment of Cancer (EORTC) core quality of life questionnaire (QLQ-C30) and its breast module (BR45). In this study, we selected 1 item per dimension based on fit to the Rasch model, patient- and clinician-rated item importance, breadth of item thresholds, and clinical relevance. These items form the core of the future Breast Utility Instrument (BUI). The future BUI will be a novel breast cancer–specific preference-based instrument that potentially will better reflect women’s preferences in clinical decision making and cost utility analyses.

Developing a preference-based measure for weight-specific health-related quality of life in adolescence: the WAItE UK valuation study protocol

INTRODUCTION

Adolescent obesity is a public health problem in the UK. The Weight-Specific Adolescent Instrument for Economic Evaluation (WAItE) has been developed as the first weight-specific health-related quality of life measure appropriate for economic evaluation, but currently cannot be used to generate quality-adjusted life years (QALYs), which are the basis of cost-utility analysis. Generic measures (such as the EQ-5D-Y or CHU-9D) may be insensitive to small but important health changes in overweight or obese adolescents. This study aims to generate a preference-based scoring algorithm for the WAItE.

METHODS AND ANALYSIS

A discrete choice experiment (DCE) will be administered to value health states described by the WAItE classification system. These health states will be presented to members of the adult general population of the UK via an online survey. A range of regression models will be used to produce the utility algorithm for the WAItE. The DCE-visual analogue scale and time trade-off (TTO) anchoring methods will be used anchor the value set on to the 0-1 QALY scale.

ETHICS AND DISSEMINATION

The Newcastle University Medical School Ethics Committee approved the study (references 4772/2020 (DCE) and 9978/2020 (TTO)). The developed algorithm can be applied to future economic evaluations of weight management interventions and treatments for adolescents.

Implementing a weight-specific quality-of-life tool for young people in primary health care: a qualitative study

Background

Obesity is thought to be one of the most serious global public health challenges of the 21st century. The primary care setting is important in terms of the diagnosis, education, and management of obesity in children and young people. This study explored the views of primary care clinicians on the implementation of a quality-of-life (QoL) tool to help young people and their families identify the impact of weight on QoL.

Aim

To assess the acceptability and feasibility of implementing the Weight-specific Adolescent Instrument for Economic-evaluation (WAItE) QoL tool for young people aged 11–18 years in primary care.

Design & setting

Qualitative study in Northern England, UK

Method

One-to-one, semi-structured interviews were conducted with a purposive sample of primary healthcare clinicians working in practices located in areas of varying deprivation in Northern England, UK. Interview transcripts were coded and analysed using framework analysis in NVivo (version 10).

Results

Participants (n = 16 GPs; n = 4 practice nurses) found the WAItE tool acceptable for them and their patients, and believed it was feasible for use in routine clinical practice. It was important to primary care clinicians that the tool would provide an overall QoL score that would be easy for GPs and nurses to interpret, to help them identify patients most in need of specialist help.

Conclusion

This study has developed a platform for further research around QoL in young people who are overweight and obese. A future feasibility study will focus on implementing the tool in a small number of primary healthcare practices.

Development of a New Quality of Life Measure for Duchenne Muscular Dystrophy Using Mixed Methods: The DMD-QoL

Objective

Based on concerns about existing patient-reported outcome measures (PROMs) for assessing quality of life (QoL) in Duchenne muscular dystrophy (DMD), we describe the mixed methods development of a new QoL PROM for use in boys and men with DMD: the DMD-QoL.

Methods

The DMD-QoL was developed in 3 stages. First, draft items were generated from 18 semistructured qualitative interviews with boys and men with DMD, analyzed using framework analysis. Second, cognitive debriefing interviews with patients (n = 10), clinicians (n = 8), and patients' parents (n = 10) were undertaken, and a reduced item set was selected and refined. Third, psychometric data on the draft items from a cross-sectional online survey (n = 102) and stakeholder input from patients and patients' parents were used to produce the final questionnaire. Patient and public involvement and engagement was embedded throughout the process.

Results

From an initial draft of 47 items, a revised set of 27 items was produced at stage 2, and this set was further refined at stage 3 to generate the DMD-QoL, a 14-item QoL PROM. The DMD-QoL is designed for use from 7 years of age by proxy report and from 10 years of age by self-report or proxy report. The final measure showed good psychometric properties.

Conclusion

The DMD-QoL is a new 14-item QoL PROM for boys and men with DMD, with demonstrable content and face validity.

Application of Rasch Analysis for Development and Psychometric Properties of Adolescents' Quality of Life Instruments: A Systematic Review

BACKGROUND

Due to the importance of assessing quality of life (QoL) in healthy and ill adolescents, the evaluation of psychometric properties of these questionnaires is important.

OBJECTIVE

To investigate the application of Rasch analysis in psychometric assessment studies on adolescents' QoL instruments, and to evaluate the quality of reporting Rasch parameters in these studies.

METHODS

This systematic review was conducted by searching for papers in electronic databases PubMed, Web of Science, EMBASE, Cochrane Library and Scopus until December 2018.

RESULTS

After screening 122 papers, 31 remained in the study. Around 68% of the studies used the Rasch analysis for instrument testing and 32% for the development of new instruments. In 77.4% of studies, both classical and Rasch methods were used parallel to data analysis. In 32.2% of studies, healthy adolescents were the main target group. The most commonly used instrument in Rasch studies was, KIDSCREEN, administered in different countries. Six Rasch parameters were reported with a higher percentage in the studies. Major reported parameters of Rasch analysis were application of the software program (96.7%), test of item fit to the Rasch model (93.5%), unidimensionality (80.6%), type of the identified mathematical Rasch model (74.1%), threshold (58%) and differential item functioning (54.8%). Based on the psychometric evaluation of the QoL instruments, 71% of studies showed acceptable results.

CONCLUSION

The application of the Rasch model for psychometric assessment of adolescents' QoL questionnaires has increased in recent decades. But, there is still no strong and commonly used critical appraisal tool or guideline for the evaluation of these papers.

A Systematic Review of the Use and Quality of Qualitative Methods in Concept Elicitation for Measures with Children and Young People

BACKGROUND

Qualitative research is recommended in concept elicitation for patient-reported outcome measures to ensure item content validity, and those developing measures are encouraged to report qualitative methods in detail. However, in measure development for children and young people, direct research can be challenging due to problems with engagement and communication.

OBJECTIVES

The aim of this systematic review was to (i) explore the qualitative and adapted data collection techniques that research teams have used with children and young people to generate items in existing measures and (ii) assess the quality of qualitative reporting.

METHODS

Three electronic databases were searched with forward citation and reference list searching of key papers. Papers included in the review were empirical studies documenting qualitative concept elicitation with children and young people. Data on qualitative methods were extracted, and all studies were checked against a qualitative reporting checklist.

RESULTS

A total of 37 studies were included. The quality of reporting of qualitative approaches for item generation was low, with information missing on sampling, data analysis and the research team, all of which are key to facilitating judgements around measure content validity. Few papers reported adapting methods to be more suitable for children and young people, potentially missing opportunities to more meaningfully engage children in concept elicitation work.

CONCLUSIONS

Research teams should ensure that they are documenting detailed and transparent processes for concept elicitation. Guidelines are currently lacking in the development and reporting of item generation for children, with this being an important area for future research.

An Updated Systematic Review of Studies Mapping (or Cross-Walking) Measures of Health-Related Quality of Life to Generic Preference-Based Measures to Generate Utility Values

BACKGROUND

Mapping is an increasingly common method used to predict instrument-specific preference-based health-state utility values (HSUVs) from data obtained from another health-related quality of life (HRQoL) measure. There have been several methodological developments in this area since a previous review up to 2007.

OBJECTIVE

To provide an updated review of all mapping studies that map from HRQoL measures to target generic preference-based measures (EQ-5D measures, SF-6D, HUI measures, QWB, AQoL measures, 15D/16D/17D, CHU-9D) published from January 2007 to October 2018.

DATA SOURCES

A systematic review of English language articles using a variety of approaches: searching electronic and utilities databases, citation searching, targeted journal and website searches.

STUDY SELECTION

Full papers of studies that mapped from one health measure to a target preference-based measure using formal statistical regression techniques.

DATA EXTRACTION

Undertaken by four authors using predefined data fields including measures, data used, econometric models and assessment of predictive ability.

RESULTS

There were 180 papers with 233 mapping functions in total. Mapping functions were generated to obtain EQ-5D-3L/EQ-5D-5L-EQ-5D-Y (n = 147), SF-6D (n = 45), AQoL-4D/AQoL-8D (n = 12), HUI2/HUI3 (n = 13), 15D (n = 8) CHU-9D (n = 4) and QWB-SA (n = 4) HSUVs. A large number of different regression methods were used with ordinary least squares (OLS) still being the most common approach (used ≥ 75% times within each preference-based measure). The majority of studies assessed the predictive ability of the mapping functions using mean absolute or root mean squared errors (n = 192, 82%), but this was lower when considering errors across different categories of severity (n = 92, 39%) and plots of predictions (n = 120, 52%).

CONCLUSIONS

The last 10 years has seen a substantial increase in the number of mapping studies and some evidence of advancement in methods with consideration of models beyond OLS and greater reporting of predictive ability of mapping functions.

Measuring Weight-Specific Quality of Life in Adolescents: An Examination of the Concurrent Validity and Test-Retest Reliability of the WAItE

OBJECTIVES

To examine the concurrent validity of the Weight-specific Adolescent Instrument for Economic evaluation (WAItE) as compared with the generic, preference-based Child Health Utility 9D (CHU-9D) and the weight-specific Youth Quality of Life-Weight (YQOL-W) and also to examine the test-retest reliability of the WAItE.

METHODS

An online survey was used to administer the 3 instruments on a sample of adolescents (aged 11-18 years). Individual responses were converted into either utility scores (CHU-9D) or health-related quality-of-life scores (WAItE and YQOL-W). A 10% subsample of the respondents also completed the WAItE 1 week after completion to assess test-retest reliability.

RESULTS

One thousand adolescents completed the online survey. There was a strong correlation between the WAItE and both the CHU-9D (0.731; P<.001) and the YQOL-W (0.747; P<.001). All 3 instruments were able to discriminate according to different weight status categories and a measure of self-assessed health. Unlike the CHU-9D or the YQOL-W, the WAItE did not show a substantial ceiling effect. The WAItE also showed acceptable levels of test-retest reliability.

CONCLUSIONS

The study results are encouraging, and illustrate that the WAItE can be used to reliably and accurately measure weight-specific outcomes in the younger population. The WAItE can also be used to assess outcomes in cost-effectiveness analysis of weight management interventions for young people, given the instrument is less likely to display ceiling effects and may thus be more sensitive in measuring change that results from interventions developed for this population.

Estimating CHU-9D Utility Scores from the WAItE: A Mapping Algorithm for Economic Evaluation

BACKGROUND

The Weight-Specific Adolescent Instrument for Economic Evaluation (WAItE) is a new condition-specific patient reported outcome measure that incorporates the views of adolescents in assessing the impact of above healthy weight status on key aspects of their lives. Presently it is not possible to use the WAItE to calculate quality adjusted life years (QALYs) for cost-utility analysis (CUA), given that utility scores are not available for health states described by the WAItE.

OBJECTIVE

This paper examines different regression models for estimating Child Health Utility 9 Dimension (CHU-9D) utility scores from the WAItE for the purpose of calculating QALYs to inform CUA.

METHODS

The WAItE and CHU-9D were completed by a sample of 975 adolescents. Nine regression models were estimated: ordinary least squares, Tobit, censored least absolute deviations, two-part, generalized linear model, robust MM-estimator, beta-binomial, finite mixture models, and ordered logistic regression. The mean absolute error (MAE) and mean squared error (MSE) were used to assess the predictive ability of the models.

RESULTS

The robust MM-estimator with stepwise-selected WAItE item scores as explanatory variables had the best predictive accuracy.

CONCLUSIONS

Condition-specific tools have been shown to be more sensitive to changes that are important to the population for which they have been developed for. The mapping algorithm developed in this study facilitates the estimation of health-state utilities necessary for undertaking CUA within clinical studies that have only collected the WAItE.