A Cost-effectiveness Analysis of Pneumococcal Vaccination in Street-involved, HIV-infected Patients

[[[ Background: ]]] Delivery of the pneumococcal vaccine (PCV) to street-involved, HIV patients in British Columbia is low due to poor compliance. Since the use of PCV is expected to reduce morbidity and mortality, it may be more cost-effective to provide the vaccine directly to clinics. [[[ Methods: ]]] Three strategies were compared for a cohort of 5000 patients: 1) administering PCV at the clinics; 2) giving a prescription for PCV and expecting patients to fill it at a pharmacy and return for administration; and 3) no administration of vaccine. Decision analysis was utilized to map the costs and outcomes of the patients over 5 years and conduct an incremental cost-effectiveness analysis from the perspective of the Ministry of Health. [[[ Results: ]]] The average cost per patient was the lowest in Strategy 1 ($549) compared to Strategy 2 ($702) and Strategy 3 ($714). For the cohort, Strategy 1 prevented 269 and 299 additional cases of pneumococcal disease and resulted in a cost savings of $535,000 and $595,000 in direct medical costs when compared to Strategies 2 and 3, respectively. The model was robust to extensive sensitivity analyses. [[[ Conclusions: ]]] The Ministry of Health should supply PCV to clinics involved in the care of street-involved HIV patients as this is the most cost-effective strategy.