Lack of diversity in antifibrotic trials for pulmonary fibrosis: a systematic review

INTRODUCTION: Social determinants of health (SDH), including age, sex, ethnicity, socioeconomic status and rurality, influence health outcomes. Clinical trials investigating antifibrotic agents for people with idiopathic pulmonary fibrosis (IPF) have been conducted in predominantly White and male populations; it is unclear whether other SDH have been considered. This study aimed to investigate active consideration and reporting of SDH in clinical trials of antifibrotic agents for people with IPF. METHODS: Three registries (ClinicalTrials.gov, ANZCTR and International Standard Randomised Controlled Trial Number (ISRCTN)) plus CENTRAL (Cochrane Central Register of Controlled Trials) were searched for clinical trials investigating antifibrotic agents for people with IPF or various progressive fibrotic ILD variants registered from 1 January 2000 until 3 September 2023. Data were extracted regarding trial phase/status, recruitment strategies and eligibility criteria. If trial results were available, SDH data from demographics and subgroup analyses were extracted. RESULTS: Of 313 records identified, 70 trials were included. The majority of trials were phase II or III (77%), 56% were completed and 61% had reported results that included eight terminated trials. All 70 trials specified age and sex, but not other SDH, within their eligibility criteria. Of 43 trials reporting results, all reported age and sex and 40 (95%) reported ethnicity. 10 387 participants were described (74% male, 77% White, 16% Asian and <1% Black). Descriptors for ethnicity varied considerably. Five trials (12%) included only White participants and three (7%) included only Asian participants. No other SDH were reported. CONCLUSIONS: SDH beyond age, sex and ethnicity were neither considered nor reported in antifibrotic IPF trials. Trial populations were predominantly male and White. There is a need to actively consider SDH to ensure diverse and representative clinical trial populations.