Abstract
BACKGROUND: Nonadherence to antiviral therapy can lead to poor clinical outcomes among patients with chronic hepatitis B (CHB). We used a claims database to evaluate risk factors for nonadherence to antiviral therapy among commercially insured patients with CHB in the United States. METHODS: We obtained data for commercially insured adult patients with CHB prescribed entecavir or tenofovir disoproxil fumarate (TDF) in 2019. Primary outcomes were adherence to entecavir and adherence to TDF. Enrollees with a proportion of days covered (PDC) ≥80% were considered adherent. We presented adjusted odds ratios (AORs) from multivariate logistic regressions. RESULTS: Eighty-three percent (n = 640) of entecavir patients were adherent, and 81% (n = 687) of TDF patients were adherent. Ninety-day supply (vs 30-day supply; AOR, 2.21; P < .01), mixed supply (vs 30-day supply; AOR, 2.19; P = .04), and ever using a mail order pharmacy (AOR, 1.92, P = .03) were associated with adherence to entecavir. Ninety-day supply (vs 30-day supply; AOR, 2.51; P < .01), mixed supply (vs 30-day supply; AOR, 1.82; P = .04), and use of a high-deductible health plan (vs no high-deductible health plan; AOR, 2.29; P = .01) were associated with adherence to TDF. Out-of-pocket spending of >$25 per 30-day supply of TDF was associated with reduced odds of adherence to TDF (vs <$5 per 30-day supply of TDF; AOR, 0.34; P < .01). CONCLUSIONS: Ninety-day and mixed-duration supplies of entecavir and TDF were associated with higher fill rates as compared with 30-day supplies among commercially insured patients with CHB.