Increasing influenza and pneumococcal immunization rates: A randomized controlled study of a senior center-based intervention

Background: Immunizations decrease morbidity from influenza and pneumococca l infections. Immunization levels remain below desired levels despite clini c-based and public education efforts. This paper describes a randomized, co ntrolled trial of a senior center-based program, which used peer-to-peer ou treach to increase pneumococcal and influenza immunization rates among an u rban senior population. Methods: Seniors were randomized to intervention or control groups. The int ervention group received educational brochures mailed with reply cards to r eport immunization status, telephone calls from senior volunteers to unimmu nized participants, and computerized immunization tracking. Immunization ra tes were obtained before and after the intervention by self-report. Results: Among participants without prior pneumococcal immunization, the pn eumococcal immunization rate among the intervention group (52.0%; 95% CI = 46.6%-57.4%) was significantly higher than that of the control group (30.9% ; 95% CI = 26.6%-35.2%) (rate ratio = 1.68; 95% CI = 1.40-2.03). Among thos e without influenza immunization in the prior year, significantly more (50. 0%; 95% CI = 40.0%-60.0%) were immunized against influenza in the intervent ion group than in the control group (23.0%; 95% CI = 15.2%-33.3%) (rate rat io = 2.17; 95% CI = 1.42-3.31). Among those with influenza immunization in the prior year, the rate ratio was 1.04 (95% CI = 1.01-1.07). Conclusions: The intervention increased both influenza and pneumococcal imm unization rates to high levels, suggesting that further progress in increas ing adult immunization coverage is possible.