Applying a Constrained Optimization Portfolio Model to Aid Prioritization of Public Health Interventions in Malaysia

Countries have constrained healthcare budgets and must prioritize new interventions depending on health goals and time frame. This situation is relevant in the sphere of national immunization programs, for which many different vaccines are proposed, budgets are limited, and efficient choices must be made in the order of vaccine introduction.

A constrained optimization (CO) model for infectious diseases was developed in which different intervention types (prophylaxis and treatment) were combined for consideration in Malaysia. Local experts defined their priority public health issues: pneumococcal disease, dengue, hepatitis B and C, rotavirus, neonatal pertussis, and cholera. Epidemiological, cost, and effectiveness data were informed from local or regionally published literature. The model aimed to maximize quality-adjusted life-year (QALY) gain through the reduction of events in each of the different diseases, under budget and intervention coverage constraints. The QALY impact of the interventions was assessed over 2 periods: lifetime and 20 years. The period of investment was limited to 15 years.

The assessment time horizon influenced the prioritization of interventions maximizing QALY gain. The incremental health gains compared with a uninformed prioritization were large for the first 8 years and declined thereafter. Rotaviral and pneumococcal vaccines were identified as key priorities irrespective of time horizon, hepatitis B immune prophylaxis and hepatitis C treatment were priorities with the lifetime horizon, and dengue vaccination replaced these with the 20-year horizon.

CO modeling is a useful tool for making economically efficient decisions within public health programs for the control of infectious diseases by helping prioritize the selection of interventions to maximize health gain under annual budget constraints.