Determinants of influenza vaccination in older adults: A nationwide community-based study in Taiwan.

Aims: Influenza vaccination (InVa) is an effective measure for preventing influenza infection, which is a major cause of morbidity and mortality in older adults. However, the determinants of InVa remain unclear.

Methods: The present study included 4756 adults aged 55 years and older who completed the baseline examination of the Healthy Aging Longitudinal Study in Taiwan. During the examination, each participant received assessments of InVa status. Comprehensive assessments of sociodemographic (age, sex, education level, marital status, living alone and occupation) and health-related factors (chronic diseases, smoking status, alcohol intake, physical activities, cognitive status and physical performance) were also carried out. The InVa rate was defined as the number of participants who reported receiving free InVa divided by the total number of candidates for free InVa. Multinomial logistic regression analysis was applied to investigate the sociodemographic and health-related determinants of InVa status.

Results: The coverage rate of InVa was 44.8% (2130/4756). Older age (adjusted odds ratio [OR; >75 years vs <65 years] 7.72, 95% CI 6.26-9.52), multiple chronic diseases (OR [≥2 vs 0)] 1.31, 95% CI 1.10-1.65) and physical activity (OR [yes vs no] 1.43, 95% CI 1.23-1.64) were positively associated with receiving InVa. A current smoking status (OR 0.67, 95% CI 0.55-0.82) was negatively associated with receiving InVa.

Conclusions: Older adults who received InVa differed from non-receivers in multiple sociodemographic and health-related characteristics. These findings support continual efforts to improve the InVa coverage rate in vulnerable populations. Geriatr Gerontol Int 2017; 17: 2396-2402.