Investigating the Added Value of the EQ-5D-5L With Two Bolt-On Items in Patients With Hemophilia

Content validity of the EQ-5D-5L with skin irritation and self-confidence bolt-ons in patients with atopic dermatitis: a qualitative think-aloud study

OBJECTIVES

Two bolt-on dimensions (skin irritation, self-confidence) have been developed for the EQ-5D-5L to improve its content validity and responsiveness in psoriasis. However, the two bolt-ons are not strictly psoriasis-specific and are potentially relevant in other skin conditions. This study aims to explore the content validity of the EQ-5D-5L with two bolt-ons in patients with atopic dermatitis (AD).

METHODS

In 2021-2022, qualitative, semi-structured interviews were conducted with 20 adult AD patients at a university dermatology clinic in Hungary. We aimed for a heterogeneous sample in terms of age, gender, education and disease severity. Patients completed the EQ-5D-5L with two bolt-ons using a think-aloud protocol. Probing questions were posed to investigate item relevance, potential conceptual overlaps, missing concepts and the appropriateness of the recall period. Interview transcripts were subjected to thematic analysis.

RESULTS

The EQ-5D-5L with the two bolt-ons covered the most important aspects of health-related quality of life in AD patients. Most patients found both the skin irritation and self-confidence bolt-ons relevant. Fifteen potential missing concepts were identified, but only two (social relationships, judgement by others) were identified by more than one patient. A smaller conceptual overlap was found between the skin irritation and pain/discomfort dimensions in 7 patients (35%). Half the patients expressed a preference for a recall period of 1 week rather than of 'today'.

CONCLUSIONS

The EQ-5D-5L with skin irritation and self-confidence bolt-ons showed good relevance, comprehensiveness and comprehensibility in patients with AD. However, in terms of comprehensiveness, social relationships and judgement by others (stigma) may be missing from the questionnaire.

Measurement properties of the EQ-5D-5L and PROPr in patients with spinal muscular atrophy

OBJECTIVES

Spinal muscular atrophy (SMA) is a rare monogenic neuromuscular disorder caused by loss of function mutations. Measuring health-related quality of life to support economic evaluations in this population is encouraged. However, empirical evidence on the performance of preference-based measures (PBMs) in individuals with SMA is limited. This study aimed to assess the psychometric properties of the EQ-5D-5L and the Patient-Reported Outcomes Measure Information System Preference measure (PROPr) in individuals with SMA.

METHODS

The data used in this study were obtained via a web-based, cross-sectional survey. All participants completed the self-reporting EQ-5D-5L and PROMIS-29 questionnaires. Information about their socioeconomic and health status was also obtained. Ceiling and floor effects, convergent and divergent validity, known-group validity, and the agreement between the two measures were assessed.

RESULTS

Strong ceiling and floor effects were observed for four dimensions of the EQ-5D-5L and three subscales, including pain intensity, pain interference, and physical function, of the PROMIS-29. All hypothesized associations between EQ-5D-5L/PROMIS-29 and other neuromuscular questions were confirmed, supporting good convergent validity. Moreover, both EQ-5D-5L and PROPr scores differentiated between impaired functional groups, demonstrating good discriminative ability. Poor agreement between the EQ-5D-5L and PROPr utility scores was observed.

CONCLUSIONS

The EQ-5D-5L and PROPr both appear to be valid PBMs for individuals with SMA. However, PROPr yielded considerably lower utility scores than EQ-5D-5L and their agreement was poor. Therefore, these two PBMs may not be used interchangeably in economic evaluations of SMA-related interventions.

Developing the health state classification system for a condition-specific preference-based measure for patients with myasthenia gravis

PURPOSE

This study aimed to generate the health state classification system (HCS) of a condition-specific preference-based measure to capture the health-related quality of life (HRQoL) of patients with myasthenia gravis (MG) from the 15-item Myasthenia Gravis Quality of Life Scale (MG-QoL15r).

MATERIALS AND METHODS

An HCS was derived from the MG-QoL15r in a large sample of 1739 patients with MG based on psychometric analysis, including factor analysis, item response theory analysis, and discussions with experts. Reliability, construct and convergent validity, and item fit of the HCS were further assessed using another sample.

RESULTS

The HCS has six dimensions: social activity, hobbies and fun activities, meeting family needs, work performance, mobility, and emotion, and it demonstrates good internal consistency reliability. The unidimensionality of the HCS was confirmed using confirmatory factor analysis. Satisfied convergent validity was supported by a significant association with the 12-item Short Form Survey (SF-12).

CONCLUSIONS

Based on a solid process of development and consultations with clinical professionals and patients, a valid MG-specific preference-based measure, MGQoL-6D, was developed. Further research will estimate the local preference weight to support the MG-related cost-utility analysis.IMPLICATION FOR REHABILITATIONA new condition-specific health state classification system (HCS) named Myasthenia gravis Quality of Life Scale (MGQoL-6D) is proposed.MGQoL-6D classifies MG health states as a combination of six dimensions with three response levels.The dimensions of the HCS are social activity, hobbies and fun activity, family needs, work performance, mobility, and emotion.The HCS and the upcoming value set of the MGQoL-6D could support the cost-effectiveness analysis of MG-related clinical and rehabilitated interventions.