Influenza Vaccination among Patients with Diabetes or Ischemic Heart Disease in Thailand: Coverage, Knowledge and Associated Factors

An influenza vaccination is recommended for patients with diabetes mellitus (DM) or ischemic heart disease (IHD) to prevent cardiovascular events, but the vaccination coverage remains low. This cross-sectional study sought to investigate vaccination coverage, knowledge level on influenza and factors associated with influenza vaccination in patients with DM or IHD treated at a tertiary hospital in northern Thailand. Patients were interviewed from August to October 2017. Of 150 patients interviewed (51.3% women, mean age of 66.7 +/- 8.3 years, 35.3% DM, 35.3% IHD, 29.3% DM and IHD), 45.3% (68/150) were vaccinated against influenza. The mean knowledge score was 9.68 +/- 1.35 (total: 11) and did not differ between those receiving the immunization and those who did not (p = 0.056). Two factors remained significantly associated with their vaccination after multivariable logistic regression analysis: knowing their right to receive free vaccinations (adjusted OR 2.32, 95% CI: 1.06-5.10, p-value: 0.035), and needing to be vaccinated (adjusted OR 3.50, 95% CI: 1.51-8.12, p-value: 0.003). Overall, the vaccine coverage was low; less than one-half of patients received the influenza vaccine, but their knowledge level was high. Possessing the right and having a need were two factors associated with vaccination. Such factors should be carefully considered to encourage patients with DM and IDH to receive the influenza vaccination.