Evaluating the correspondence between the EQ-5D-5L and disease severity and quality of life in adults and adolescents with cystic fibrosis.

BACKGROUND: The EQ-5D is the recommended measure to capture health-related quality of life (HRQoL), recognised for use in health technology appraisal bodies. In order to assess whether it is appropriate to use the EQ-5D for making decisions about the cost-utility of treatments in cystic fibrosis (CF), this study assesses the performance of the EQ-5D-5L in adults and adolescents with CF. METHOD: This was a cross-sectional observational survey study of patients with CF attending a single large CF centre. Participants were asked to complete a survey that included two HRQoL measures; the EQ-5D-5L and CF Quality of Life (CFQoL) questionnaires. RESULTS: Among 213 participants, the median EQ-5D-5L index score was 0.76 (IQR 0.66 - 0.84) and the visual analogue (EQ-VAS) was 70 (60 - 80). Both the EQ-5D index and EQ-VAS discriminated between disease severity based on lung function (p = 0.01 and p < 0.01, respectively) and pulmonary exacerbation (p = 0.02 and p < 0.01, respectively); however, EQ-VAS differentiated between more lung function severity groups compared to EQ-5D index. The EQ-5D-5L demonstrated convergent validity as its dimensions, index score, and EQ-VAS had significant correlations with most CFQoL domains. Though, EQ-VAS significantly predicted more domains of CFQoL (4 domains) compared to EQ-5D index (only 1 domain). CONCLUSION: The generic EQ-5D-5L performed adequately in discriminating between CF disease severity, and its index score and EQ-VAS had moderate correlations with CFQoL. However, using a complementary condition-specific measure alongside the EQ-5D-5L can provide better insight of HRQoL in CF and benefit the process of cost-utility analysis.

Exploring the nature of perceived treatment burden: a study to compare treatment burden measures in adults with cystic fibrosis [version 1; peer review: 2 approved].

Background: Despite the importance of reducing treatment burden for people with cystic fibrosis (CF), it has not been fully understood as a concept. This study aims to quantify the treatment burden perceived by CF adults and explore the association between different validated treatment burden measures. Methods: This is a cross-sectional observational study of CF adults attending a single large UK adult center. Participants completed an online survey that contained three different treatment burden scales; CF Questionnaire-Revised (CFQ-R) subscale, CF Quality of Life (CFQoL) subscale, and the generic multimorbidity treatment burden questionnaire (MTBQ). Results: Among 101 participants, the median reported treatment burden by the CFQ-R subscale was 55.5 (IQR 33.3 - 66.6), the CFQoL subscale was 66.6 (IQR 46.6 - 86.6), and the MTBQ reversed global score was 84.6 (IQR 73.1 - 92.3). No correlation was found between respondents' demographic or clinical variables and treatment burden measured via any of the three measures. All treatment burden measures showed correlations against each other. More treatments were associated with high treatment burden as measured by the CFQ-R, CFQoL subscales, and the MTBQ. However, longer treatment time and more complex treatment plans were correlated with high treatment burden as measured by the CFQ-R and CFQoL subscales, but not with the MTBQ. Conclusions: Treatment burden is a substantial issue in CF. Currently, the only available way to evaluate it is with the CF-specific quality of life measure treatment burden subscales (CFQ-R and CFQoL); both indicated that treatment burden increases with more treatments, longer treatment time, and more complex treatments.