Assessment of vaccine coverage following the introduction of a publicly funded pneumococcal vaccine program for the elderly in Victoria, Australia

In 1998, a publicly funded pneumococcal vaccine program was introduced for persons aged ≥ 65 years in Victoria, Australia. In 2000, vaccine coverage over the previous 5 years was assessed through a telephone survey of 385 randomly selected subjects aged ≥ 65 years. Self-reported pneumococcal vaccine coverage within the previous 5 years was 46.0% (95% CI 40.5-51.6). Self-report was validated against the medical records of the nominated provider for 278 (72%) subjects. Among this subgroup, self-reported coverage was 51.1% but was 57.9% according to medical records (positive predictive value 91.5%, negative predictive value 77.2%, sensitivity 80.7%, specificity 89.7%). After accounting for response bias among those subjects for whom self-report was not validated, the revised estimate of pneumococcal vaccine coverage within the previous 5 years was 50.5% (95% CI 44.8-56.1). Comparison of vaccine coverage over time suggests the introduction of the publicly funded program in Victoria has dramatically increased coverage among the elderly.