Empirical Research on the Demand for Influenza Vaccination Among the Elderly,

Abstract

Purpose: This paper analyses what factors determine the demand for vaccination among the elderly as a high risk group. Using the estimation results, this paper then evaluates how legal requirements and/or subsidies affect their demand. Methods: Original data were obtained from two surveys, conducted by the author, given to two groups: elderly people living with descendants, and elderly people living without descendants. The surveys contained information about the elderly, the household, experience of influenza during the last season, immunization during this time, and a hypothetical questionnaire about immunization for purposes of Conjoint Analysis. Three estimations are performed for actual behaviour, Conjoint Analysis and Joint Estimation, the latter combining the first two estimations. Results: Among estimation results, factors such as cost, number of immunizations, availability of immunization at night or on the weekend, and legal requirements heavily affect the demand for immunization. Experience of influenza and immunization in the preceding season is one of the most important determinants. In addition, the superiority of the Joint Estimation method is confirmed. Conclusions: The estimation results imply that about 8.9 million elderly people will have a demand for vaccination if there is no cost and it is legally recommended. If the cost is 6000 yen (about US$50) and there is no legal recommendation, demand for vaccination will be reduced to about 3.2 million elderly people. An increase in cost from free vaccination to just 500 yen (about US$4) depresses demand from 1.6 million elderly people. On its own, legal recommendations for vaccination can push up demand by 2.0 million elderly persons.