Hepatitis B birth dose vaccination patterns in the military health System, 2014-2018

Background: Since 2005, the universal hepatitis B (HepB) birth dose has been recommended for all medically stable infants weighing ≥2,000 g at birth. The timing of the birth dose provides a critical safeguard and prevents infection among infants born to HBsAg-positive mothers not identified prenatally. We assess infant HepB vaccination in the U.S. Department of Defense's Military Health System (MHS) to identify trends in vaccination coverage and sociodemographic factors associated with non-receipt of the birth dose, receiving the first HepB vaccine >3 days of life, and not receiving any HepB vaccine in the first 18 months of life utilizing parental refusal codes. To our knowledge, this is one of the first studies assessing trends in parental refusal of the HepB birth dose utilizing administrative claims parental refusal codes.

Methods: We conducted a retrospective cohort analysis of MHS live births from January 1, 2014 through December 31, 2018 utilizing administrative claims data. Data were included from 44 hospitals in 24 unique states, territories, or countries. We analyzed diagnosis codes for vaccine refusal and vaccination and current procedural terminology (CPT) codes to identify vaccination patterns. Generalized linear mixed effects models with a logit link were used to assess factors associated with vaccination patterns.

Results: HepB birth dose vaccination coverage increased from 79.6% in 2014 to 88.1% in 2018 (p < .0001). Refusal rates also increased from 3.7% in 2014 to 4.5% in 2018 (p < .0001). The percentage of patients with missing diagnosis codes for vaccine refusal or vaccination decreased from 16.7% in 2014 to 7.4% in 2018. Factors associated with non-receipt of the birth dose included earlier year of birth, white maternal race, higher maternal age, higher birth order, and longer infant length of stay in hospital.

Conclusion: Vaccination coverage for HepB birth dose is high in the MHS and increased over time; concurrently, refusal rates also increased over time. Utilizing administrative claims data has the benefit of differentiating reasons for non-receipt of the birth dose over time.