Future prediction of health expectancy considering the target of Health Japan 21 (the second term)

OBJECTIVES: We attempted to predict health expectancy in Japan for the period between 2011 and 2020, considering the target of Health Japan 21 (the second term) that future gains in health expectancy be larger than in life expectancy. METHODS: We used data from Japanese national statistics. Health expectancy between 2011 and 2020 was predicted using the Sullivan method under the assumption that future mortality was equal to the estimate in Population Projections for Japan (January 2012), and under three scenarios of future prevalence of bad health status. RESULTS: The numbers of expected years without activity limitation at birth for males and females in 2020 were predicted as 71.2 and 74.3, respectively, under the scenario that prevalence of activity limitation was constant since 2010; 71.4 and 74.5 under the scenario that the prevalence followed the recent trend; and 71.7 and 74.9 under the scenario that the prevalence decreased with such a rate that future gains in health expectancy were equal to in life expectancy. The rate of decrease in the prevalence in 2010-2020 in the last scenario was estimated to be 0.95 in males and 0.96 in females. The numbers of expected years with subjective well-being at birth in 2020 predicted under above three scenarios were between 69.5 and 71.2 in males and between 72.9 and 74.6 in females. The rate of decrease in the last scenario was estimated to be 0.96 in males and 0.97 in females. The numbers of expected years without care needs at age 65 in 2020 predicted under above three scenarios were between 18.0-18.2 in males and between 21.2-21.5 in females. The rate of decrease in the last scenario was estimated to be 0.90 in males and 0.91 in females. CONCLUSION: The health expectancy in 2011-2020 was predicted under some scenarios of future prevalence of bad health status. The rate of decrease in the future prevalence of bad health status was estimated with a view to the accomplishment of the target of Health Japan 21 (the second term).