2205. Clinical Burden of Pneumococcal Disease in US Adults Aged 65 Years and Above with Chronic or Immunocompromising Conditions

BACKGROUND: The presence of chronic and immunocompromising conditions is associated with a disproportionately high risk of developing pneumococcal disease at older ages. The objective of this study was to quantify the risk of all-cause pneumonia (ACP) and invasive pneumococcal disease (IPD) in older US adults aged 65 years and older with underlying medical conditions. METHODS: A retrospective observational study was conducted using the Humana claims database. The study cohorts were identified at January 1 of each calendar year of observation from 2012 to 2017 and comprised adults aged 65 years and older with continuous enrollment for at least one year before and at least one year after January 1 of each year. For each yearly cohort, medical conditions were identified during the one year before each calendar year and episodes of ACP and IPD were identified during the corresponding 1-year follow-up period from January 1 to December 31. Individuals were stratified into 3 groups: those without any medical conditions of interests (healthy), those with chronic conditions (at-risk) and those with immunocompromising conditions (high-risk). Rate of ACP or IPD was expressed as the number of cases per 100,000 person-years and the rate ratio (RR) was expressed as the rate of pneumococcal disease of patients with medical conditions divided by the rate of pneumococcal disease in healthy adults. RESULTS: Of the 10,766,827 adults included in the study, 75% of adults had an underlying medical condition linked to an increased risk of pneumococcal disease. In adults with at-risk conditions, rates of ACP and IPD were 3.1 and 3.6 times the rate in healthy adults, respectively. In adults with high-risk conditions, rates of ACP and IPD were 4.1 and 5 times the rate in healthy adults, respectively. Rate of pneumococcal disease increased substantially with the addition of medical conditions: RR for ACP and IPD increased from 2.1 and 2.2, respectively, in adults with one at-risk conditions to 4.8 and 6.2, respectively, among adults with 2 or more at-risk conditions. CONCLUSION: Despite recommendations of universal pneumococcal vaccination in older adults aged 65 years and above in the United States, the burden of pneumococcal disease remains high, particularly among those with chronic and immunocompromising conditions. DISCLOSURES: All authors: No reported disclosures.