Health state utilities associated with treatment burden in cystic fibrosis: a patient valuation study

Abstract

BACKGROUND
While recent advancements in the treatment of cystic fibrosis (CF) have improved survival, reducing high levels of treatment burden remains a priority issue for many people with CF (pwCF). However, economic evaluations of novel interventions may fail to capture their impact on treatment burden due to a lack of suitable outcome measures. This study aimed to estimate health state utilities (HSUs), for changes in treatment burden associated with different CF treatments.

RESEARCH QUESTION
What value do pwCF place on changes in treatment burden associated with intravenous antibiotic treatment of pulmonary exacerbations, inhaled medicines, and physiotherapy?

STUDY DESIGN
AND METHODS: Adults attending a specialist CF center were invited to participate in a web-based time trade-off interview. Participants valued their own health, and five health state vignettes describing varying levels of intensity of physiotherapy, inhaled, and IV antibiotic treatment. HSUs for additional instances of each treatment type were estimated using mixed effect linear regression models.

RESULTS
Fifty one people with CF completed the interview (median age, 30 years; range, 19-66); 53% were female; mean FEV(1) % predicted, 65% [SD, 20%]).

Mean utility scores for own health were very similar between the EQ-5D index value (0.81, SD 0.20) and the TTO value (0.82, SD 0.20), however limited concordance was observed at the individual level. Adjusted utility decrements associated with treatment burden were -0.037 (SE 0.008) for an additional annual IV antibiotic treatment, -0.029 (SE 0.014) for an additional daily physiotherapy session, and -0.019 (SE 0.013) for an additional daily inhaled medicine.

INTERPRETATION
Increasing treatment burden was associated with decreasing HSU values. The utility decrements associated with treatment burden changes suggest meaningful differences in health-related quality of life (HRQoL) for pwCF. These findings align with existing literature on the impact of treatment burden on HRQoL, and highlight the importance of considering treatment burden in economic evaluations of interventions in CF.