Factors associated with continued adherence to influenza vaccination in the elderly.

Abstract

OBJECTIVE: We aimed to analyze the factors influencing continued adherence to influenza vaccination in elderly persons vaccinated in the preceding season. METHODS: Using a population-based vaccination registry, we evaluated the proportion of persons vaccinated against influenza in Navarre, Spain, in the 2010-11 season among non-institutionalized persons aged 65 years or over who had been vaccinated in the 2009-10 season. Logistic regression was used to analyze the influence of sociodemographic, clinical and health care factors. RESULTS: Of the 64,245 persons vaccinated against influenza in the 2009-10 season, 87% were vaccinated in the 2010-11 season. Continued adherence to vaccination increased with the number of physician visits per year. It was lower in women, in the 65-69 and ≥ 95 year age-groups, in those hospitalized or diagnosed with any major chronic condition in the previous year, and in persons with hematological cancer or dementia. Health districts and physicians with higher coverage in the previous season continued to have higher adherence in the following season. CONCLUSIONS: People vaccinated against influenza in one season tend to be vaccinated in the following one. Sociodemographic, clinical and health care factors have a moderate effect on the continuity of vaccination, with the most important factor being the treating physician.