Understanding treatment burden in cystic fibrosis, its association with health-related quality of life and implications for the economic evaluation

Abstract

Background: The continuous advancements in cystic fibrosis (CF) treatments have improved the longevity of people with CF (pwCF). Eventually, the increased number and complexity of treatments elevate treatment burden. Decision-making bodies, such as NICE, prefer using EQ-5D as the generic health-related quality of life (HRQoL) measure in economic evaluations, however, limited data exist on its use in CF. Despite the importance of reducing treatment burden for pwCF, it remains an underexplored concept and is not yet considered in economic evaluation. This thesis aimed to provide evidence to enhance the focus on patient-centred outcomes through measuring HRQoL and treatment burden for pwCF to support economic evaluation and resource allocation. Systematic review: A systematic search explored methods used to measure CF-related treatment burden. Seventeen studies underwent narrative synthesis to identify the most utilised burden measures. Methods: The thesis consisted of four studies. Study 1 described HRQoL using EQ-5D-5L and its discriminatory ability toward CF disease severities. Study 2 assessed EQ-5D-5L convergent validity with the condition-specific CFQoL; evaluated HRQoL and well-being differences before and during COVID-19 pandemic. Study 3 described the nature of perceived treatment burden using three measures. Study 4 explored treatment burden association with EQ-5D utility score and considered how treatment burden might be captured in economic evaluations. Results: The EQ-5D-5L discriminated between CF disease severities and demonstrated convergent validity with CFQoL. High levels of perceived treatment burden among pwCF, were associated with increased daily treatments, treatment time, and treatment complexity. The EQ-5D utility score partially captures treatment burden. Conclusion: Reducing treatment burden is the desirable outcome for pwCF. This research revealed high levels of burden perceived by pwCF, emphasising the importance of addressing this issue. By incorporating treatment burden in economic evaluation, decision-makers can make more informed cost-effectiveness decisions which reduce burden, optimise resource allocation, and improve HRQoL for pwCF.