Ursodeoxycholic Acid Treatment Preferentially Improves Overall Survival Among African Americans With Primary Biliary Cholangitis

BACKGROUND: We used data from the Fibrotic Liver Disease Consortium to evaluate the impact of ursodeoxycholic acid (UDCA) treatment across race/ethnicity, gender, and clinical status among patients with primary biliary cholangitis. METHODS: Data were collected from "index date" (baseline) through December 31, 2016. Inverse Probability of Treatment Weighting was used to adjust for UDCA treatment selection bias. Cox regression, focusing on UDCA-by-risk factor interactions, was used to assess the association between treatment and mortality and liver transplant/death. RESULTS: Among 4,238 patients with primary biliary cholangitis (13% men; 8% African American, 7% Asian American/American Indian/Pacific Island [ASINPI]; 21% Hispanic), 78% had ever received UDCA. The final multivariable model for mortality retained age, household income, comorbidity score, total bilirubin, albumin, alkaline phosphatase, and interactions of UDCA with race, gender, and aspartate aminotransferase/alanine aminotransferase >= 1.1. Among untreated patients, African Americans and ASINPIs had higher mortality than whites (adjusted hazard ratio [aHR] = 1.34, 95% confidence interval [CI] 1.08-1.67 and aHR = 1.40, 95% CI 1.11-1.76, respectively). Among treated patients, this relationship was reversed (aHR = 0.67, 95% CI 0.51-0.86 and aHR = 0.88, 95% CI 0.67-1.16). Patterns were similar for liver transplant/death. UDCA reduced the risk of liver transplant/death in all patient groups and mortality across all groups except white women with aspartate aminotransferase/alanine aminotransferase >= 1.1. As compared to patients with low-normal bilirubin at baseline (<= 0.4 mg/dL), those with high-normal (1.0 > 0.7) and mid-normal bilirubin (0.7 > 0.4) had significantly higher liver transplant/death and all-cause mortality. DISCUSSION: African American and ASINPI patients who did not receive UDCA had significantly higher mortality than white patients. Among African Americans, treatment was associated with significantly lower mortality. Regardless of UDCA treatment, higher baseline bilirubin, even within the normal range, was associated with increased mortality and liver transplant/death compared with low-normal levels.