Standing orders program of pneumococcal vaccination for hospitalized elderly patients in Hong Kong: A cost-effectiveness analysis

Background: Clinical studies support a standing orders program (SOP) to improve vaccine uptake. We aimed to examine the potential cost-effectiveness of a pneumococcal vaccination SOP for Hong Kong elderly in a hospital setting.

Methods: A decision-analytic model was designed to compare the outcomes of inpatients 65 years of age or older who were eligible for pneumococcal vaccination. Two vaccination approaches were evaluated: (1) vaccination SOP, and (2) no program (control group). Outcome measures included direct medical costs, invasive pneumococcal disease-associated mortality rates, quality-adjusted life year (QALY) losses, and incremental cost per QALY saved (ICER).

Results: In the base-case analysis, mortality and QALY losses were lower and costs were higher in the SOP group when compared to the control group. The base-case ICER of the SOP group was $59,762 (all dollar amounts are in US$) per QALY saved. One-way sensitivity analyses found ICER to be sensitive to the probability of invasive pneumococcal disease among the unvaccinated elderly. Using 1× the gross domestic product per capita of Hong Kong ($43,497) and the United States ($150,000) as willingness-to-pay thresholds, SOPs were the preferred option in 37.2% and 97.5% of 10,000 Monte Carlo simulations, respectively.

Conclusions: The pneumococcal vaccination SOP for hospitalized elderly patients appeared to reduce QALY losses at a higher cost. The cost-effective acceptance of SOPs is highly dependent on the willingness-to-pay threshold.