Background: Influenza is a major cause of morbidity and mortality in Japan and worldwide, especially for people of >65 years old and those with high-risk medical conditions. Although the influenza vaccine is effective in reducing the morbidity and mortality, the vaccine coverage rate has not increased adequately in Japan, compared with western countries.
Objective: Our aim was to assess whether medical and personal characteristics are associated with receiving influenza vaccination in Japanese patients.
Methods: Out-patients of a city hospital were recruited for a case-control study between November 1998 and February 1999. Cases were 98 out-patients aged 18 years or older who received influenza vaccination. Controls were 112 non-vaccinated out-patients matched with cases for primary physician and date of clinic visit. The candidates were interviewed by telephone and asked to respond to a 26-item questionnaire. The data were analysed using multiple logistic regression models.
Results: The factors associated with the acceptance of influenza vaccination were: (i) recommendation by a family member and/or a close friend [odds ratio (OR) 17.74; 95% confidence interval (CI) 1.95-161.77]; (ii) belief in influenza vaccine efficacy (OR 10.55; 95% CI 3.42-32.49); (iii) having a family member and/or friends who had been vaccinated before (OR 6.44; 95% CI 2.37-17.50); (iv) physician's recommendation (OR 4.03; 95% CI 1.42-11.37); and (v) knowledge about the influenza vaccine (OR 3.06; 95% CI 1.02-9.20). Fear of adverse reactions (OR 0.21; 95% CI 0.07-0.66) was the sole factor associated with non-acceptance of influenza vaccine.
Conclusion: Patients in Japan are likely to be greatly influenced by their family members or close friends in their decision of whether to accept influenza vaccination, unlike US patients who make health care decisions on their own. When implementing an influenza vaccination programme, this effect of cultural background observed in Japan should be taken into account in other countries.