Patient Characteristics Determine Differences in the Influenza Vaccination Rate More so Than Practice Features

Abstract

Background. World-wide each year 30–55% of the target population is vaccinated against influenza. Determinants of successful vaccination programs are not clear. This study was aimed at identifying practice- and patient-related factors that determine differences in vaccination rates. Methods. Data on patients of the target population were extracted from the computerized medical record systems of 48 family practices. Information about organizational factors was collected by a questionnaire for GP's. Multilevel logistic regression analyses were used to assess the determinants. Results. Of all patients at risk (42,426), 76% were vaccinated. The vaccination rate for patients above age 65 was 15% higher when a medical indication was present. Patients with cardiac diseases or diabetes mellitus attained a relatively higher vaccination rate than other groups at risk. Special hours for vaccination led to significantly higher vaccination rates for the elderly and cardiac patients. Patients below 65 years of age were particularly influenced by special information pamphlets. Conclusion. Explanations of differences in uptake rates were found at the patient level. All practices in this study were well organized; nevertheless, subgroup analyses showed that special vaccination hours for elderly people and information pamphlets for young people could improve results further.