Using Quantitative and Qualitative Approaches to Understand Racial Disparities in Adult Vaccination

Background: One proposed explanation for the persistence of racial disparities in adult immunizations is that minority patients receive primary care at practices that differ substantively from practices where white patients receive care. This study used both quantitative and qualitative methods to assess physician and practice factors contributing to disparities in a sample of inner-city, urban, and suburban practices in low to moderate income neighborhoods. Methods: Pneumococcal polysaccharide vaccine (PPV) and influenza vaccination rates were determined from medical record review in a sample of 2021 elderly (aged >= 65 years) patients. Their physicians were surveyed about office systems for adult immunizations and structured observations of practice physical features, and operations were conducted. Case studies of practices with lowest and highest rates and the largest racial disparities are presented. Results: Overall, weighted PPV vaccination rate was 60%, but rates differed significantly by race (65.8% for whites vs 36.5% for minorities, P < .001 by stratified Cochran-Mantel-Haenszel test). Two of 6 minority panels had PPV rates less than 20%. Overall, weighted influenza vaccination rate, as measured by receipt of the vaccine in 3 of the 5 most recent seasons, was 51.9%, but rates also differed significantly by race (55.6% for whites vs 36.2% for minorities, P < .03, by stratified Cochran-Mantel-Haenszel test). Conclusions: Low rates in 2 minority panels, racial disparity between minorities and whites in mixed panels, and between-panel variation in rates contributed to the overall differences in vaccination rates by race.