Abstract
Purpose In 2001, Japan launched a nationwide subsidy program for influenza immunization of the elderly, whose implementation was devolved to municipalities. Rapid appraisal of the financial impact and utilisation are helpful for evaluating public programs. The government appraised uptake rate with a resource-consuming complete survey. In the present study, the authors carried out a simple and easy sample survey, with a simple random sampling method, to estimate averages of co-payment, subsidy, and total price for one vaccination. The utility of a simple random sampling method for a nationwide survey is also discussed.
Method A total of 300 individuals were randomly selected from about 22 million senior citizens in the 2001/2 season. A questionnaire is sent to their municipal authorities, inquiring about the price of vaccination, the target population size, and the numbers of vaccinated seniors from 2001/2 to 2004/5. Annual changes and the differences between urban and rural areas were examined with analysis of variance and regression analysis.
Results The response rate is 94.0%. Nationwide average prices of vaccination in terms of co-payment, subsidy, and total price changes from 2001/2 to 2004/5 were as follows: the co-payments were ¥1134, ¥1136, ¥1139, ¥1129 and ¥1148; the subsidies were ¥2972, ¥2955, ¥2966, ¥2954 and ¥2941; and the total prices are ¥4194, ¥4169, ¥4178, ¥4156 and ¥4142. No statistically significant differences were found in the annual rates. Vaccine uptake rates from 2001/2 to 2003/4 were 29.9%, 37.8%, 46.1%, 49.6%, showing a statistically significant increase.
Conclusion These are the first estimates of price and uptake rates of influenza vaccination for the elderly in Japan by a sample survey method. The results demonstrate that the co-payment, subsidies, and the total price have not changed significantly since the program started, but that uptake has improved. The results also suggest that simple random sampling methods are useful for rapid appraisal of the nationwide trends with public programs devolved to municipalities.
