Methods: We conducted a retrospective database study of administrative claims from the 2008-2015 MarketScan Commercial Claims and Encounters, Medicare Supplemental, and Multi-State Medicaid databases. Completion of 2 and 3 doses of HepA and HepB, respectively, and compliance with the 2- and 3-dose recommended schedules were measured. Individuals age 19 and older at first dose were included if they had 18 months of continuous health plan enrollment prior to the first HepA dose and 6 months prior to the first HepB dose. Median time to completion, the proportion of patients who completed 2 and 3 doses, and adherence to the recommended schedule within specific time periods of the first dose were estimated using Kaplan-Meier survival curves.
Results: Average age at initiation was 39.4 years for HepA and 40.9 for HepB. Males composed 45% and 41.2% of HepA and HepB initiators, respectively. Overall, 27.1% of individuals received a second dose of HepA within the recommended 18 months; 32.1% of individuals received a second HepA dose within 42 months. For HepB, 51.3% of individuals received a second dose within 13 months of the first dose and 29.4% received a third dose within 16 months of the first dose. Among those who received a second dose, 52.5% received a third dose within 14 months.
Conclusion: Adherence to multi-dose adult vaccines in the U.S. is suboptimal. For both HepA and HepB vaccines, less than 1/3 of individuals completed the series suggesting that there may be significant barriers to be addressed to optimize completion of multi-dose vaccines in real-world settings.
RTI Health Solutions:
GSK: RTI - Health Solutions, received funding via a contractual agreement with GSK to perform the work contributing to this research , Research support
D. Zhang, Merck: Employee , Salary
K. Johnson, Merck & Co., Inc.: Employee , Salary