Objective: To analyse the direct medical costs and effectiveness of vaccinating adults aged between 18 and 64 years and elderly persons > or = 65 years of age with the 23-valent pneumococcal polysaccharide vaccine.
Design and setting: This was a decision-analytic modelling study from the societal perspective in Belgium. The analysis compared 'vaccination' with 'no vaccination and treatment'.
Methods: Calculations were based on the assumption that vaccination is as effective against all pneumococcal infections as it is against invasive pneumococcal disease. Data on the incidence of pneumococcal pneumonia and meningitis, frequency of hospitalisation, mortality rates and vaccine effectiveness were derived from the international literature. Costs were derived from analysis of historical data for cases of pneumococcal infection in Belgium.
Results: Vaccinating 1000 adults between the ages of 18 and 64 years gains approximately 2 life-years in comparison with the no vaccination option. However, to realise these additional health benefits requires additional costs of 11,800 European Currency Units (ECU; 1995 values) per life-year saved. Vaccinating 1000 elderly people (> or = 65 years) leads to > 9 life-years gained as well as a small monetary benefit of ECU1250. An extensive sensitivity analysis did not greatly affect the results for the elderly population: vaccination in this age group always remained favourable, and thus it is clearly indicated from an economic point of view. A crucial assumption for both age groups is that the effectiveness of the vaccine holds for all pneumococcal pneumonia. It is clear that the results will become less favourable if this assumption is dropped.
Conclusions: Preventing pneumococcal infections by vaccination clearly benefits people's health. Reimbursement can be recommended for the elderly group; however, more accurate epidemiological data are still needed to make decisions concerning routine pneumococcal vaccination in adults < 65 years of age. Unfortunately, the issue of whether the effectiveness of the vaccine holds for all pneumococcal pneumonia is as yet unresolved in the medical literature.