Abstract
BACKGROUND: Medication adherence is essential in managing cystic fibrosis (CF). The role of socioeconomic factors for medication adherence in people with CF is poorly understood, and their differential impact across the life course is underexplored. This study investigates associations between measures of socioeconomic status (SES)-educational attainment, household income, and health insurance type-and adherence to CF medications across age groups. METHODS: We conducted a cross-sectional analysis of data collected during the validation of the Daily Care Check-In, a measure of adherence barriers in people with CF. Adherence was measured as a composite medication possession ratio (cMPR) averaged across five CF-specific medications, with data collected from pharmacy records. Sociodemographic and clinical data were collected through self-report and medical record review. RESULTS: A total of 405 participants completed the study, with an overall cMPR of 45.6%, lowest (38.5%) among young adults (aged 18-26 years) and highest (53.0%) among adolescents (aged 13-17 years). Lower household income and lack of college degree were associated with lower cMPR, more interference from adherence barriers, and decreased self-efficacy, as well as with increased depressive and anxiety symptoms. Similar associations, but less consistent, were observed for public health insurance. When stratified by age, associations between SES measures and adherence were most evident in adolescents, followed by adults, but absent in young adults, bringing into focus challenges with measuring SES in the 18-25 years age group. CONCLUSION: Lower SES is associated with worse medication adherence, more interference from adherence barriers, and lower self-efficacy. Associations vary by SES measure and age group, calling for a nuanced approach to adherence interventions in this population.