Cost Effectiveness Analysis of influenza vaccination for people aged 65 or older in Japan

2003 Fiscal Year Final Research Report Summary

• Project/Area Number: 14572123
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Medical sociology
• Research Institution: TSUKUBA UNIVERSITY
• Principal Investigator: OKUBO Ichiro TSUKUBA UNIVERSITY, TSUKUBA UNIVERSITY, SOCIAL MEDICINE, PROFESSOR (40323307)
• Co-Investigator(Kenkyū-buntansha): TAKAHASHI Hideto TSUKUBA UNIVERSITY, SOCIAL MEDICINE, Associate Professor (80261808)
• Project Period (FY): 2002 – 2003
• Keywords: influenza / CEA / cost-effective ratio / incremental cost-effective ratio / decision tree / YOLS / sensitivity analysis / Monte Carlo simulation

Research Abstract

Epidemics of influenza break out annually throughout the world, although their extent and severity vary widely. Recurring epidemics are known to have consequences such as morbidity that disrupts work in school, company, and elsewhere. Although influenza affects entire population, individuals, such as persons aged 65 years and over, or persons with pre-existing disease are at higher risk of becoming serious enough to be hospitalized or die. The number of those individuals is increasing in developed countries, as the aging of population progresses. Consequently, they confront with the problem of serious morbidity and mortality from influenza.
Japan launched a government-founded age-base national influenza immunization program in December 2001. Under this program, every person aged 65 and over is entitled to a subsidy for influenza vaccination. One-dose of vaccination administrated to a voluntary vaccinee in the target population will be paid partially by public expenditure.
Studies have re ported that age-base influenza vaccination program to those aged 65 years or older to be cost-saving or cost-effective in some countries or regions, but cost-effectiveness of the current immunization program in Japan has not been reported. In this study we performed an economic evaluation to investigate the following two questions in detail. A) Is the current subsidy strategy efficient? B) Is there any alternative strategy of immunization which could be more efficient?
A decision-analytic model was constructed to investigate the cost and effectiveness of two age-base immunization programs and two risk-base immunization programs. Accompanied by a series of sensitivity analyses and Monte Carlo simulation our study demonstrates that from the perspective of society, 1) current influenza vaccination program for people aged 65 and over in Japan is cost-effective from the perspective of society (US$6, 282/YOLS in base case), 2) risk-base strategy has favorable incremental cost-effective ratios than age-base strategy ; however, both of risk-base and age-base immunization strategies are reasonably cost-effective.