Impact of CFTR modulators on caregiver burden in cystic fibrosis: a cross-sectional study in Brazil

Abstract Objective To assess caregiver burden, health-related quality of life, and work productivity among primary caregivers of individuals with cystic fibrosis (CF) in Brazil, comparing caregivers of patients using elexacaftor/tezacaftor/ivacaftor (ETI) with those of non-users, and analyzing differences according to the age group of the care recipient. Methods This cross-sectional study was conducted between September and November 2025 using an online questionnaire. Eligible participants were primary caregivers of individuals with CF living in Brazil. Collected data included sociodemographics, CFTR modulator use, caregiving time, and out-of-pocket health-related expenses. Validated instruments included the 12-item Zarit Burden Interview (ZBI-12), the EQ-5D-3L (utility index and Visual Analogue Scale), and the Work Productivity and Activity Impairment Questionnaire for Caregivers (WPAI: CG). Descriptive analyses and group comparisons were stratified by ETI use and age group of the care recipient. Results A total of 174 caregivers from all Brazilian regions participated; 90.2% were mothers, with a median age of 35 years (IQR: 28–45). The individuals receiving care had a median age of 11 years (IQR: 7–14) among modulator users and 3 years (IQR: 1–7) among non-users, and 44.8% used CFTR modulators. Caregivers of non-modulator users dedicated significantly more time to daily caregiving (300 min [IQR: 180–300] vs. 180 min [IQR: 90–240]; p = 0.002) and reported more frequent consultations ( p = 0.003). ZBI-12 scores were higher in the no-modulator group (20.0 [IQR: 16.0–25.2] vs. 15.5 [IQR: 11.2–23.0]; p = 0.006), with the greatest difference observed among caregivers of children under 5 years (20.0 vs. 14.0; p = 0.003), a group currently without access to modulators through the public health system. EQ-VAS was lower in the no-modulator group (65.0 [IQR: 50.0–80.0] vs. 70.0 [IQR: 50.0–80.0]; p = 0.041). Absenteeism (15.8% [IQR: 0.0–28.6] vs. 0.0% [IQR: 0.0–16.4]; p = 0.034), presenteeism (50.0% [IQR: 5.0–60.0] vs. 20.0% [IQR: 0.0–50.0]; p = 0.048), and activity impairment (50.0% [IQR: 22.5–70.0] vs. 30.0% [IQR: 0.0–60.0]; p = 0.011) were significantly higher among caregivers without modulator access. Conclusion Use of CFTR modulators was associated with lower caregiver burden, better health perception, and reduced work productivity loss.