Representation of minoritized people with cystic fibrosis in the Cystic Fibrosis Therapeutics Development Network clinical trials.

rationaleBlack and Hispanic people with cystic fibrosis (PwCF) experience worse health outcomes related to pulmonary disease compared with White, non-Hispanic PwCF. Improving outcomes in minoritized PwCF is a crucial need in the CF community, but prior evidence suggests that these communities are underrepresented in CF clinical research.

objectiveTo determine whether CF clinical studies are representative of the overall CF population.

methodsThe study cohort included participants from recent CF transmembrane conductance regulator modulator studies: Characterizing CFTR Modulated Changes in Sweat Chloride and their Association with Clinical Outcomes (CHEC-SC), A Prospective Study to Evaluate Biological and Clinical Effects of Significantly Corrected CFTR Function (PROMISE), Prospective Longitudinal Study of CFTR-dependent Disease Profiling in CF (PROSPECT), and the G551D Observational Study. Persons seen at the same centers who were eligible for these studies based on the inclusion and exclusion criteria but did not enroll were used as a comparator cohort from the Cystic Fibrosis Foundation Patient Registry (CFFPR). Rates of study enrollment were assessed separately for Black race and Hispanic ethnicity versus non-Hispanic White PwCF. Propensity-weighted Poisson regression models were used to account for potential confounders in the relationship between race and study participation.

resultsDemographic characteristics were compared between 3594 PwCF in the 4 modulator studies with 14 888 individuals from the CFFPR who were eligible but did not enroll. Enrollees were younger (median age 19 years), more likely to have had at least 3 clinic visits per year, and more likely to live within 30 miles of the study site. Black and Hispanic PwCF were less likely to have private insurance and less likely to live far from study centers. Multivariable analysis revealed that Black individuals were significantly less likely than non-Hispanic White individuals to enroll in CHEC-SC and PROMISE, with a 17% and 32% lower likelihood, respectively. Hispanic individuals had a 34% lower enrollment rate than non-Hispanic White individuals in PROMISE but had a higher enrollment in PROSPECT. Differences in enrollment rates were greater at sites with fewer minority participants.

conclusionThese results suggest that Black and Hispanic PwCF are, overall, significantly less likely to be included in CF clinical research than non-Hispanic White PwCF. Future research is needed to better understand if these differences are upheld in studies with varying inclusion/exclusion criteria and clinical sites.