Pneumococcal vaccination coverage among adults newly diagnosed with underlying medical conditions and regional variation in the U.S.

BACKGROUND: The Centers for Disease Control and Prevention's Advisory Committee on Immunization Practices recommends pneumococcal vaccination for adults with chronic or immunocompromising conditions to prevent pneumococcal disease, yet vaccination rates are low and have limited information on regional variation. This study examines factors associated with pneumococcal vaccination in adults with underlying conditions and describes regional variation in vaccination across the U.S. METHODS: Using IBM MarketScan Commercial Database and Medicare Supplemental Database, this retrospective cohort study included adults ages 19-64 newly diagnosed with chronic (i.e. diabetes, chronic heart, lung, or liver disease, alcohol or tobacco dependence) or immunocompromising (i.e. cancer, chronic renal disease, organ transplant, HIV/AIDS, and asplenia) conditions in 2013. Adults were followed up until the time of pneumococcal vaccination, death, or December 31, 2019, whichever came first. Cox proportional hazards model was used to examine factors associated with vaccination. Vaccination rate was calculated by metropolitan statistical area (MSA) and visually represented on a U.S. map. RESULTS: 255,330 adults were included. Vaccination rate increased from 6.0% to 21.1% among adults with one year and five years of follow-up, respectively. It took 2.4 years on average for adults to receive vaccination after initial diagnosis. Adults ages 50-64, 35-49 (relative to 19-34) or receiving influenza vaccination were more likely to receive pneumococcal vaccinations. Adults with HIV/AIDS were more likely and those with other conditions were less likely to be vaccinated than those with diabetes. Adults being diagnosed by other providers were less likely to be vaccinated than those diagnosed by primary care providers. Vaccination rate varied largely across MSAs, ranging from 0.0% (Ames, IA; Cheyenne, WY) to 34.0% (Ann Arbor, MI). CONCLUSION: Pneumococcal vaccination remains low and most adults with underlying conditions are unvaccinated. Insights into factors associated with vaccination, including regional variability, can help to increase pneumococcal vaccination.