High level of medication adherence is required to lower mortality in patients with chronic hepatitis B taking entecavir: A nationwide cohort study

Abstract

It is unclear whether suboptimal adherence contributes to adverse clinical outcomes in patients with chronic hepatitis B (CHB). Moreover, there is no consensus regarding the optimal level of drug adherence. This was a population-based historical cohort study including 51?975 adult CHB patients treated with entecavir (0.5?mg/d orally). Data were obtained from the Korean national health insurance service claims database, which covers >99% of the entire population, between 2007 and 2015. Medication adherence was categorized as high (proportion of days covered [PDC], ≥90%; n?=?32?089), intermediate (PDC, 80%-89%; n?=?10?197) and low (PDC, <80%; n?=?9689). During a median 4.5?years (maximal 9?years) of follow-up in 51?975 CHB patients treated with entecavir, multivariable analyses revealed that the risk of mortality/transplantation was significantly greater in the low-adherers (adjusted hazard ratio [HR], 1.38; P?<.001) and intermediate-adherers (adjusted HR, 1.44; P?<.001) than the high-adherers (P for trend?