Pneumococcal vaccination in older adults: An initial analysis of social determinants of health and vaccine uptake

•Pneumococcal vaccination rates are suboptimal in older adults.•Adult vaccine hesitancy is poorly understood.•Social determinants may be influencing pneumococcal vaccine uptake.•Rural areas and those with low health literacy may be prone to lower vaccine rates.•Access to information may also influence pneumococcal vaccine-seeking behavior. To examine the potential influence of social determinants of health on pneumococcal vaccination in older American adults. This study used nationwide, US Medicare claims data from 2013 to 2016 to assess uptake of pneumococcal vaccination among adults in the first year after turning age 65. Patients were followed from the point of being 65 years of age and initially enrolled in traditional fee-for-service Medicare or a Medicare Advantage plan through the subsequent year and observed for pneumococcal vaccination in outpatient clinics and pharmacies. Publicly-available data on select social determinants of health were incorporated and guided by the World Health Organization vaccine hesitancy matrix. Logistic regression determined predictors of vaccination while controlling clinical and demographic characteristics. A total of 307,488 and 74,995 adults aged 65 years were identified from Medicare Advantage and Medicare fee-for-service claims, respectively, and 21.1% of Medicare Advantage and 38.2% of Medicare fee-for-service patients received a pneumococcal vaccine in the first year after turning 65. Those residing in urban areas had a higher likelihood of pneumococcal vaccination in both the Medicare Advantage (OR: 1.31; 95% CI: 1.267–1.344) and Medicare fee-for-service (OR: 1.53; 95% CI: 1.450–1.615) cohorts. Additionally, residing in areas of higher health literacy or communities with more democratic voters were consistently associated with a higher odds of pneumococcal vaccination regardless of Medicare type. Results also pointed to a synergistic relationship between receiving the influenza vaccine and also being vaccinated against pneumococcal disease. Social determinants of health, including local health literacy, poverty, residing in more liberal areas, and access to information, may be influencing the pneumococcal vaccine-related decisions of older adults. However, additional factors associated with the vaccine hesitancy matrix and more granular data (e.g., zip code-level) are needed to fully determine the impact in this and other vaccines recommended in older adults.