Evaluation of Pulmonary Fibrosis Outcomes by Race and Ethnicity in US Adults

Importance: Pulmonary fibrosis (PF) is characterized by progressive scarring of lung tissue and poor survival. Racial and ethnic minority populations face the greatest risk of morbidity and mortality from disparities impacting respiratory health, but the pattern of age at clinically relevant outcomes across diverse racial and ethnic populations with PF is unknown. Objective: To compare the age at PF-related outcomes and the heterogeneity in survival patterns among Hispanic, non-Hispanic Black, and non-Hispanic White participants. Design, Setting, and Participants: This cohort study included adult patients with a PF diagnosis and used data from prospective clinical registries: the Pulmonary Fibrosis Foundation Registry (PFFR) for the primary cohort and registries from 4 geographically distinct tertiary hospitals in the US for the external multicenter validation (EMV) cohort. Patients were followed between January 2003 and April 2021. Exposures: Race and ethnicity comparisons between Black, Hispanic, and White participants with PF. Main Outcomes and Measures: Age and sex distribution of participants were measured at the time of study enrollment. All-cause mortality and age at PF diagnosis, hospitalization, lung transplant, and death were assessed in participants over 14 389 person-years. Differences between racial and ethnic groups were compared using Wilcoxon rank sum tests, Bartlett 1-way analysis of variance, and χ2 tests, and crude mortality rates and rate ratios were assessed across racial and ethnic categories using Cox proportional hazards regression models. Results: In total, 4792 participants with PF were assessed (mean SD age, 66.1 11.2 years; 2779 58.0% male; 488 10.2% Black, 319 6.7% Hispanic, and 3985 83.2% White); 1904 were in the PFFR and 2888 in the EMV cohort. Black patients with PF were consistently younger than White patients (mean SD age at baseline, 57.9 12.0 vs 68.6 9.6 years; P < .001). Hispanic and White patients were predominantly male (Hispanic: PFFR, 73 of 124 58.9% and EMV, 109 of 195 55.9%; and White: PFFR, 1090 of 1675 65.1% and EMV, 1373 of 2310 59.4%), while Black patients were less likely to be male (PFFR, 32 of 105 30.5% and EMV, 102 of 383 26.6%). Compared with White patients, Black patients had a lower crude mortality rate ratio (0.57 95% CI, 0.31-0.97), but for Hispanic patients, the mortality rate ratio was similar to that of White patients (0.89; 95% CI, 0.57-1.35). Mean (SD) hospitalization events per person were highest among Black patients compared with Hispanic and White patients (Black: 3.6 [5.0; Hispanic, 1.8 1.4; and White, 1.7 1.3; P < .001). Black patients were consistently younger than Hispanic and White patients at first hospitalization (mean SD age: Black, 59.4 11.7 years; Hispanic, 67.5 9.8 years; and White, 70.0 9.3 years; P < .001), lung transplant (Black, 58.6 8.6 years; Hispanic, 60.5 6.1 years; and White, 66.9 6.7 years; P < .001), and death (Black, 68.7 8.4 years; Hispanic, 72.9 7.6 years; and White, 73.5 8.7 years; P < .001). These findings remained consistent in the replication cohort and in sensitivity analyses within prespecified deciles of age groups. Conclusions and Relevance: In this cohort study of participants with PF, racial and ethnic disparities, especially among Black patients, were found in PF-related outcomes, including earlier onset of death. Further research is essential to identify and mitigate the underlying responsible factors.