Impact of partial reimbursement on hepatitis B antiviral utilization and adherence

Abstract

To determine the impact of partial reimbursement for antivirals on antiviral utilization and adherence for chronic hepatitis B patients. This was a retrospective cohort study. Two separate cohorts were enrolled, including 14163 and 16288 chronic hepatitis B outpatients, respectively. These patients were referred to Beijing You'an Hospital before and after the new partial reimbursement for antivirals, which was implemented on July 1, 2011. Demographic characteristics (including medical insurance status), routine biochemical, virological and serology laboratory test results, and antiviral agents' prescription information were collected from an electronic database. Patients were also defined as new and existing patients according to treatment history. Antiviral utilization, medication possession ratio and persistence rate were calculated and compared among the patients with different characteristics. A questionnaire survey was conducted among 212 randomly sampled outpatients from the same hospital to confirm the validity of the electronic database. Propensity score matching was used to adjust the distribution of patient's characteristics which may influence the antiviral utilization. χ(2) test or ANOVA was adopted and multivariate logistic regression was used to determine the factors associated with antiviral utilization and good adherence. A total of 13364 outpatients from each cohort were enrolled after the propensity score matching. The antiviral utilization rate for the insured patients increased from 57.4% to 75.9% (P < 0.0001) after the reimbursement, and the rate among those who paid out-of-pocket increased from 54.9% to 56.7% (P = 0.028). Approximately 71% of the patients had a medication possession ratio of more than 80% in each cohort before reimbursement. This increased to 79.2% and 73.1% for insured patients and those who paid out-of-pocket, respectively (P < 0.0001). Insured patients and those who paid out-of-pocket had the similar persistence rates before reimbursement. But after reimbursement, insured patients had higher persistence rates than those who paid out-of-pocket at 6 (86.5% vs 81.5%, P < 0.0001), 9 (79.7% vs 69.9%, P < 0.0001), 12 (73.4% vs 61.9%, P < 0.0001), and 15 mo (66.6% vs 53.1%, P < 0.0001). The reimbursement could significantly improve adherence for the insured patients than those who paid out-of-pocket even after adjusting other covariates, with an interaction odds ratio of 1.422 (95%CI: 1.220-1.657, P < 0.0001). The questionnaire survey supported the validity of the electronic database. The reimbursement policy shows a positive impact on antiviral utilization as well as adherence for insured chronic hepatitis B patients.