Cost-effectiveness of augmenting universal hepatitis B vaccination with immunoglobin treatment

Abstract

Objective: To compare the cost-effectiveness of hepatitis B virus (HBV) control strategies combining universal vaccination with hepatitis B immunoglobulin (HBIG) treatment for neonates of carrier mothers.

Methods: Drawing on Taiwan's experience, we developed a decision-analytic model to estimate the clinical and economic outcomes for 4 strategies: (1) strategy V-universal vaccination; (2) strategy S-V plus screening for hepatitis B surface antigen (HBsAg) and HBIG treatment for HBsAg-positive mothers' neonates; (3) strategy E-V plus screening for hepatitis B e-antigen (HBeAg), HBIG for HBeAg-positive mothers' neonates; (4) strategy S&E-V plus screening for HBsAg then HBeAg, HBIG for all HBeAg-positive, and some HBeAg-negative/HBsAg-positive mothers' neonates.

Results: Strategy S averted the most infections, followed by S&E, E, and V. In most cases, the more effective strategies were also more costly. The willingness-to-pay (WTP) above which strategy S was cost-effective rose as carrier rate declined and was <$4000 per infection averted for carrier rates >5%. The WTP below which strategy V was optimal also increased as carrier rate declined, from $1400 at 30% carrier rate to $3100 at 5% carrier rate. Strategies involving E were optimal for an intermediate range of WTP that narrowed as carrier rate declined.

Conclusions: HBIG treatment for neonates of HBsAg carrier mothers is likely to be a cost-effective addition to universal vaccination, particularly in settings with adequate health care infrastructure. Targeting HBIG to neonates of higher risk HBeAg-positive mothers may be preferred where WTP is moderate. However, in very resource-limited settings, universal vaccination alone is optimal.

FIGURE 1

This decision analysis tree outlines 4 immunization strategies. The compared strategies are represented as branches from a square decision node. Probabilistic events are represented as circular chance nodes. Chance nodes with only 1 outgoing branch indicate events that occur with certainty. Outcomes are represented as triangular terminal nodes. neg, negative; pos, positive.

FIGURE 2

HBV infections and costs of 4 hepatitis B immunization strategies among a hypothetical cohort of 100 000 newborns across HBV carrier rates from 30% to 1%. A, HBV infections per 100 000 newborns; B, cost (in millions of US dollars) per 100 000 newborns.

FIGURE 3

The optimal strategy of a hepatitis B control program according to the ICER (in US dollars per incremental infection averted) at different HBV carrier rates. Lines show the ICERs of different strategies compared with the next most effective strategy. The labels mark the areas divided by the 3 ICER lines, indicating the range of conditions under which each strategy is optimal.