LAUSR

OBJECTIVE This study investigated the patterns of pneumococcal disease vaccination, the time between two different pneumococcal vaccine doses and factors associated with series completion. METHODS A retrospective claims database analysis was conducted using the Clinformatics DataMart™ database. Adults who turned 65 years between January 1st, 2013 to June 30th, 2017 and were continuously enrolled (≥15 months) in the Medicare Advantage plans to June 30th, 2017 were included in this study. Pneumococcal vaccination patterns included: PCV13-PPV23, PPV23-PCV13, or receiving PPV23 or PCV13 only. Pneumococcal vaccination series completion was defined as receiving PCV13-PPV23 or PPV23-PCV13 from 65 years old to June 30th, 2017 while non-completion was defined as receiving only PCV13 or only PPV23 from 65 years old to June 30th, 2017. A multivariable logistic regression model was used to identify factors associated with pneumococcal vaccination series completion. RESULTS A total of 224,132 adults were included in this study. Most received no pneumococcal vaccination (49%), while 34.3% received only one vaccine. Series completion occurred in 16.8% of adults. Some adults received only one vaccination: 11.6% received PPV23 and 22.7% received PCV13. The mean time between vaccinations was 420.8 days (approximately 14 months) for the PCV-PPV23 series, and 595.5 days (approximately 20 months) for the PPV23-PCV13 series. Adults were significantly more likely to complete pneumococcal vaccination series if they had at least one doctor's office, outpatient visit, or pharmacy visit versus no visits, or received an influenza vaccination in the first year after turning 65 years than those who did not (All: P < 0.001). CONCLUSION Despite the 2014 recommendation, percentages of pneumococcal vaccination series completion were found to be low, aligning with recent literature. This highlights the need to improve series completion, given the increased risk and associated economic burden of pneumococcal disease in adults aged ≥65 years.