Producing a preference-based quality of life measure for people with Duchenne muscular dystrophy: a mixed-methods study protocol

"You Take This Day by Day, Come What May": A Qualitative Study of the Psychosocial Impacts of Living with Duchenne Muscular Dystrophy

INTRODUCTION

Studies have reported health-related quality-of-life impacts of Duchenne muscular dystrophy (DMD); however, further research is needed to understand how those with DMD experience their condition and how psychosocial impacts evolve over time in response to disease progression. This qualitative study explores the social and emotional implications of key transitions, challenges and adaptations throughout the disease course from the perspective of patients and family caregivers.

METHODS

Semi-structured interviews were conducted with men and boys with DMD, and/or their caregivers, in the USA. Thematic analysis was used to examine patterns in data collected across the interviews.

RESULTS

Nineteen participants were included. Three major themes were identified: (1) barriers to participation are multifaceted; (2) an emotional journey shaped by 'inevitable progression;' (3) family provides critical tangible and emotional support. This study illustrates that psychosocial impacts of DMD are shaped by knowledge of the condition's natural history alongside other factors including the extent of social barriers, personal growth and adaptation, and family support.

CONCLUSIONS

Findings provide insight into the strength and resilience with which individuals and their families respond to daily challenges and major clinical milestones and highlight the relative importance of loss of upper limb function as a transition in DMD affecting health-related quality-of-life.

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.

Estimating health state utilities in Duchenne muscular dystrophy using the health utilities index and EQ-5D-5L

BACKGROUND

The progression of Duchenne muscular dystrophy (DMD) is characterized by loss of ambulation, respiratory insufficiency, cardiomyopathy, and early mortality. DMD profoundly impacts health-related quality-of-life (HRQoL). However, few health state utility data exist; published utilities tend to be derived from small samples for a limited number of health states and are often based on caregiver-reported patient health status. This study estimated utility values for varied clinical and functional health states in DMD, based on patient-reported health status.

METHODS

Individuals with DMD in the US aged 12-40 years completed the EQ-5D (5-level) and Health Utilities Index (HUI) preference-based instruments. Based on responses to a clinical questionnaire, participants self-classified into functional health states according to level of lower and upper limb function, use of respiratory support, and presence of cardiomyopathy. Mean [standard deviation (SD)] utility and EQ-5D visual analogue scale (VAS) scores were estimated according to health state; and median (interquartile range) attribute levels calculated to understand which domains of health are most severely affected in DMD.

RESULTS

Of 63 males with DMD, mean (SD) age was 19.8 (6.1) years and 11 (17.5%) were ambulatory. Mean (SD) utility values were 0.92 (0.08; HUI2), 0.84 (0.20; HUI3), and 0.84 (0.13; EQ-5D) for ambulatory patients without cardiomyopathy (n = 10). For non-ambulatory patients with moderately impaired upper limb function, night and daytime ventilation without cardiomyopathy, mean (SD) utilities were 0.49 (0.07) for the HUI2, 0.16 (0.15) for the HUI3 and 025 (0.14) for the EQ-5D. Mean (SD) VAS scores for the same health states were 91 (9) and 83 (21), respectively. In addition to impairments in mobility/ambulation, and self-care, attributes like usual activities and pain also showed notable effects of DMD.

CONCLUSIONS

In DMD, although a relationship between disease progression and HRQoL is observed, there is large variability in utility within functional health states, and across instruments. Utility values for less severe non-ambulatory health states described by level of upper limb function are novel. These utility values, derived based on direct patient feedback rather than from caregiver report, are relevant to individuals of varying functional statuses and augment scarce DMD-specific utility data.

Estimating Societal Cost of Illness and Patients' Quality of Life of Duchenne Muscular Dystrophy in Egypt

OBJECTIVES

Duchenne muscular dystrophy (DMD) is a rare neuromuscular disease that causes substantial economic burden. This study aims to measure the DMD cost from societal perspective and the quality of life (QOL) of the Egyptian patients.

METHODS

We conducted interviews with caregivers of patients with DMD. The questionnaire included demographics, healthcare resource use, and nonmedical and indirect costs. Total disease burden was estimated with a bottom-up approach. QOL was measured with a disease-specific tool. Costs and utilities were stratified by the disease stage.

RESULTS

Caregivers of 97 patients with DMD were interviewed. The mean annual per-patient cost of $17 485 (SD ± 9240) was estimated resulting in a total burden of $138 217 043 in Egypt. Nonmedical costs made up the largest category representing 54% followed by medical then indirect costs. Informal care made the greatest contribution of nonmedical costs whereas physiotherapy was the largest medical subcategory. Nonmedical costs were highest in stage 3 and lowest at early stages whereas medical costs were almost steady among all stages with differences in individual subcategories. Of all medical costs, 95% were out of pocket. The mean utility score was 0.43 (± 0.31), which decreases with disease progression.

CONCLUSION

Our study quantified the huge economic burden of DMD on the society and how it differs in different stages. Almost the whole burden is paid by households resulting in catastrophic expenditures, which leads to reduced compliance and quality of care. QOL is also severely compromised. Our findings can inform future healthcare policies and economic evaluation of new DMD therapies.

A comprehensive qualitative framework for health-related quality of life in Duchenne muscular dystrophy

PURPOSE

Duchenne muscular dystrophy (DMD) is a rare x-linked neuromuscular condition predominantly affecting boys and men. There is a paucity of research qualitatively detailing the lived experience of health-related quality of life (HRQoL) for people with DMD. The aim of this study was to identify a comprehensive framework for better understanding HRQoL in DMD.

METHODS

Eighteen boys and men (aged 7 to ≥ 40 years) with DMD were recruited from charity Duchenne UK, a DMD support group, and 5 UK National Health Service Trusts. Semi-structured interviews were conducted using a topic guide informed by a review into HRQoL in DMD. Generic, preference-based, patient-reported outcome measures (PROs) were used as prompts. Interviews were audio recorded, transcribed verbatim and analysed using framework analysis.

RESULTS

Thirty-seven themes were coded, within seven categories. Six categories were conceptualised as components of HRQoL (autonomy, daily activities, feelings and emotions, identity, physical aspects, social relationships) and one considered an input (healthcare, support, and environment). Three additional themes were used to code feedback on the generic PROs (CHU-9D, EQ-5D, HUI). Social relationships received most coverage in the data and was noted as an omission from the PROs.

CONCLUSION

A 30-item framework for HRQoL in DMD has been developed, which was used as input into a new condition-specific HRQoL PRO and preference-based measure: the DMD-QoL. The data has value in its own right in highlighting the lived experience of HRQoL for people with DMD and as a barometer for assessing the content of HRQoL PROs for use in DMD.

What Matters for Evaluating the Quality of Mental Healthcare? Identifying Important Aspects in Qualitative Focus Groups with Service Users and Frontline Mental Health Professionals

Background

Evaluating quality in mental healthcare is essential for ensuring a high-quality experience for service users (SUs). Policy-defined quality indicators, however, risk misalignment with the perspectives of SUs and mental healthcare professionals (MHPs). There is value in exploring how SUs and frontline MHPs think quality should be measured.

Objectives

Our study objectives were to: (1) identify aspects that SUs and MHPs deem important for assessing quality in mental healthcare to help support attribute selection in a subsequent discrete choice experiment and (2) explore similarities and differences between SU and MHPs’ views.

Methods

Semi-structured qualitative focus groups (n = 6) were conducted with SUs (n = 14) and MHPs (n = 8) recruited from a UK National Health Service Trust. A topic guide was generated from a review of UK policy documents and existing data used to measure quality in mental healthcare in England. Transcripts were analysed using a framework analysis.

Results

Twenty-one subthemes were identified, grouped within six themes: accessing mental healthcare; assessing the benefits of care; co-ordinated approach; delivering mental healthcare; individualised care; and role of the person providing care. Themes such as person-centred care, capacity and resources, and receiving the right type of care received more coverage than others. Service users and MHPs displayed high concordance in their views, with minor areas of divergence.

Conclusions

We developed a comprehensive six-theme framework for understanding quality in mental healthcare from the viewpoint of the SU and frontline MHP, which can be used to help inform the selection of a meaningful set of quality indicators in mental health for research and practice.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40271-022-00580-0.

Deriving a Preference-Based Measure for People With Duchenne Muscular Dystrophy From the DMD-QoL

OBJECTIVES

This study generates a preference-based measure for capturing the quality of life of people with Duchenne muscular dystrophy (DMD) from a new measure of quality of life, DMD-QoL.

METHODS

A health state classification system was derived from the DMD-QoL based on psychometric performance of items, factor analysis, and item response theory analysis. Preferences for health states described by the classification system were elicited using an online discrete choice experiment survey with life years as an additional attribute, from members of the UK general population (n = 1043). Discrete choice experiment data was modeled using a conditional fixed-effects logit model and utility estimates were directly anchored on the 1 to 0 full health-dead scale.

RESULTS

The health state classification system has 8 dimensions: mobility, difficulty using hands, difficulty breathing, pain, tiredness, worry, participation, and feeling good about yourself. The standard model had mostly statistically significant coefficients and reflected the instrument's monotonic structure. However, 2 dimensions had inconsistent coefficients (where utility increased as health worsened) and a consistent model was estimated that merged adjacent inconsistent severity levels. The best state defined by the classification system has a value of 1 and the worst state has a value of -0.559.

CONCLUSION

The modeled results enable DMD-QoL-8D utility values to be generated using DMD-QoL or DMD-QoL-8D data to generate QALYs for people with DMD. QALYs can then be used to inform economic models of the cost-effectiveness of interventions in DMD. Future research comparing the psychometric performance of DMD-QoL-8D to existing generic preference-based measures, including EQ-5D-5L, is recommended.

Valuing child and adolescent health: a qualitative study on different perspectives and priorities taken by the adult general public

BACKGROUND

Quantitative health preference research has shown that different "perspectives", defined here as who is imagined to be experiencing particular health states, impact stated preferences. This qualitative project aimed to elucidate this phenomenon, within the context of adults' valuation of child and adolescent health states.

METHODS

Six focus groups with 30 members of the UK adult public were conducted between December 2019 and February 2020 and analysed using framework analysis. Each focus group had two stages. First, participants individually completed time trade-off tasks and a pairwise task (mirroring a discrete choice experiment without duration) for two EQ-5D-Y health states, assuming a series of perspectives: (a) themselves at current age; (b) another adult; (c) 10-year old child; (d) themselves as a 10-year old child. Second, a semi-structured discussion explored their responses.

RESULTS

Participants' views were often heterogeneous, with some common themes. Qualitatively, participants expressed a different willingness to trade-off life years for a 10-year old child versus themselves or another adult, and this differed by the health profile and child imagined. The same health states were often viewed as having a different impact on utility for a 10-year old child than adults. Imagining a 10-year old child is difficult and there is variation in who is imagined. Participants found answering based on their own-adult perspective most acceptable. There were no strong preferences for prioritising child health over working-age adults' health.

CONCLUSIONS

If an adult sample is used to value child- and adolescent-specific health states it is important to consider the perspective employed. Members of the adult public provide different responses when different perspectives are used due to differences in the perceived impact of the same health states. If adults are asked to imagine a child, we recommend that sampling is representative for parental status, since this can affect preferences.

Symptoms and impacts of ambulatory nonsense mutation Duchenne muscular dystrophy: a qualitative study and the development of a patient-centred conceptual model

Background

Duchenne muscular dystrophy is a rare genetic neuromuscular disorder, which can result in early death due to disease progression. Ataluren is indicated for the treatment of nonsense mutation Duchenne muscular dystrophy, in ambulatory individuals aged two years and older. This study explored the symptoms and impacts of nonsense mutation Duchenne muscular dystrophy and experience with ataluren.

Methods

Qualitative interviews were conducted with caregivers in the UK. Interviews were conducted by telephone, were recorded and transcribed. Data were analysed using thematic analysis and saturation was recorded.

Results

Ten interviews were conducted with parents of individuals aged 4–19 years. Key symptoms included muscle weakness and muscle breakdown, which were associated with limitations in physical function and pain. These impacted individuals’ daily activities, social activities and emotional wellbeing. These concepts and relationships were illustrated in a conceptual model, along with positive and negative moderating factors. Experience with ataluren and changes since initiation with treatment were discussed.

Conclusion

Individuals with nonsense mutation Duchenne muscular dystrophy experience a range of interrelated symptoms and functional issues which impact their broader health-related quality of life. Treatments which address this high unmet need have the potential to improve the health-related quality of life of these individuals.

Supplementary Information

The online version contains supplementary material available at 10.1186/s41687-021-00341-x.

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.

Characterizing health state utilities associated with Duchenne muscular dystrophy: a systematic review

Background

Preferences for health states for Duchenne muscular dystrophy (DMD) are necessary to assess costs and benefits of novel therapies. Because DMD progression begins in childhood, the impact of DMD on health-related quality-of-life (HRQoL) affects preferences of both DMD patients and their families. The objective of this review was to synthesize published evidence for health state utility from the DMD patient and caregiver perspectives.

Methods

A systematic review was performed using MEDLINE and Embase, according to best practices. Data were extracted from studies reporting DMD patient or caregiver utilities; these included study and patient characteristics, health states considered, and utility estimates. Quality appraisal of studies was performed.

Results

From 888 abstracts, eight publications describing five studies were identified. DMD utility estimates were from preference-based measures presented stratified by ambulatory status, ventilation, and age. Patient (or patient–proxy) utility estimates ranged from 0.75 (early ambulatory DMD) to 0.05 (day-and-night ventilation). Caregiver utilities ranged from 0.87 (for caregivers of adults with DMD) to 0.71 (for caregivers of predominantly childhood patients). Both patient and caregiver utilities trended lower with higher disease severity. Variability in utilities was observed based on instrument, respondent type, and country. Utility estimates for health states within non-ambulatory DMD are under reported; nor were utilities for DMD-related health states such as scoliosis or preserved upper limb function identified.

Conclusion

Published health state utilities document the substantial HRQoL impacts of DMD, particularly with disease progression. Additional research in patient utilities for additional health states, particularly in non-ambulatory DMD patients, is warranted.

Electronic supplementary material

The online version of this article (10.1007/s11136-019-02355-x) contains supplementary material, which is available to authorized users.

Another Rush to Judgment: The Imaginary Worlds of ICER and Recommendations in Duchenne Muscular Dystrophy

Previous commentaries in the Formulary Evaluation section of INNOVATIONS in Pharmacy have pointed to the lack of credibility in modeled claims for cost-effectiveness and associated recommendations for pricing by the Institute for Clinical and Economic Review (ICER). The principal objection to ICER reports has been that their modeled claims fail the standards of normal science: they are best seen as pseudoscience. The purpose of this latest commentary is to consider the recently released ICER report for Duchennemuscular dystrophy (DMD). As ICER has continued in the case of DMD to apply its modeled cost utility framework with consequent recommendations for pricing adjustments, these recommendations also lack credibility. This commentary emphasizes again not only why the ICER methodology fails to meet the standards of normal science but to point to the importance in rare diseases for accelerated approval, while recognizing that evidence generation will continue.While this assessment of the ICER DMD model does not imply any support for this methodology, a key point is the application of quality of life measures which fail to capture the experience of patients with DMD and, importantly, the interests of both patients and caregivers. While ICER would argue that even with a limited evidence base it is important to address issues of pricing and access for new products, their reports are used as justification for coverage and reimbursement by insurers and health system decision makers without recognition of their lack of scientific merit. This rush to judgement by ICER must raise concerns about potentially adverse formulary decisions that result in access restrictions on new products. If ICER is to make a contribution to the entry of new products in the health market place then it should consider an alternative methodology that generates claims that are empirically evaluable in a timeframe relevant to health decision makers. As it stands, ICER's recommendation should be rejected. This is not a research program that meets accepted scientific standards but one that relies on the willingness of an audience to accept the proposition that evidence is constructed not discovered.