Factors associated with pneumococcal vaccination uptake by cancer survivors

This study aimed to evaluate factors associated with pneumococcal vaccination uptake (PVU) of cancer survivors. A total of 2032 Korean adult cancer survivors diagnosed between June of 1975 and February of 2018 have participated. Information on PVU status and selected variables were collected through self-administered questionnaires and medical record review. Factors associated PVU were investigated using multiple logistic regression analysis. PVU rate markedly differed by age strata and cancer sites: 73.9% for elderly (≥ 65 years) survivors and 34.6% for younger (< 65 years) survivors and 73.4% for lung cancer survivors and 42.1% for non-lung cancer survivors. Regular physical exercise was associated with higher PVU in both age groups: Odds ratio (OR) and 95% confidence interval (CI) were 1.52 (1.20, 1.94) for younger and 1.78 (1.09, 2.90) for elderly survivors. Complementary medication use was positively associated with PVU with borderline significance in both age groups. However, the association of PVU with other factors differed between the two age groups. In younger survivors, a positive association with PVU was evident for longer time lapse after cancer diagnosis, chronic disease, and living with spouse/or partner, while cancer stage, educational achievement, and alcohol use were inversely associated PVU. On the other hand, multi-modality (≥ 3) cancer treatment was inversely associated with PVU only in elderly survivors. PVU of Korean cancer survivors was suboptimal in younger survivors and non-lung cancer survivors. Factors associated with PVU differed between younger and elderly survivors, and more diverse factors were identified for younger survivors. In order to promote adherence to PVU in cancer survivors, careful consideration of high-risk factors for non-immunization within cancer survivorship context would be necessary together with free-of-charge vaccination policy.