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.