Influenza vaccination coverage among high-risk groups in 11 European countries

BACKGROUND: National vaccination coverage rates for individuals at increased risk of influenza-related complications represent a useful public health indicator of preparedness. We compared European countries regarding (i) vaccination coverage among high-risk groups and (ii) the likelihood that high-risk individuals reported influenza vaccination compared with those at lower risk.

METHODS: We used data from the Survey of Health, Ageing and Retirement in Europe (SHARE) collected in 2004-05. Adults aged ≥ 50 years from 11 countries provided self-reports of an influenza vaccination in the previous year (n = 16,913). We defined four high-risk groups (age ≥ 65 years, presence of vascular disease, chronic lung disease or diabetes) and calculated vaccination coverage with 95% confidence intervals for each country. Country-specific multivariable logistic regression was used to estimate odds ratios (ORs) for membership in a high-risk group and vaccination.

RESULTS: The Netherlands had the highest influenza vaccination coverage in high-risk groups (≥ 75% in any group) while Greece had the lowest (<27% in any group). Older age was positively associated with report of vaccination in all countries, but the strength of this association varied from an OR of <2 (Germany) to >13 (The Netherlands). The ORs for the chronic disease groups was ≥ 4 for The Netherlands and were considerably lower (and often not statistically significant) for the other countries.

CONCLUSION: Influenza vaccination coverage among high-risk groups varies considerably between European countries. Our findings highlight potential opportunities for reducing influenza-related complications through support for vaccination programs that target high-risk individuals more effectively.