Aging and Diversity of Medical Needs: Cost of illness of cerebrovascular disease in each prefecture of Japan
Authors: Hasegawa Tomonori , Matsumoto Kunichika , Hirata Koki 
Published: April 2019

Background: Aging in Japan is advancing most rapidly in the world, and is expected to increase demand of medical services more in near future. Aging is uneven and progress of the aging varies from regions resulting in great differences in medical needs. In order to supply the needs for medical services, Japanese government developed “Regional Medical Vision”, which estimates the near future requirements for medical resources. However, this is a plan for redistribution of medical resources taking into only future changes of population composition based on current situation. In fact, each region has diversity of medical needs, and it is difficult to use average medical needs even if they are adjusted by population structures. In consideration of such situation, we tried to estimate the social burden of major diseases of each region in order to estimate the medical needs. We picked up cerebrovascular diseases (CVD, ICD10 code: I60 - I69) and dementia (ICD10code: F01, F03, G30), and calculated their social burden of all 47 prefectures in Japan that have great authority for health policy.

Method: Modifying the COI method developed by Rice D, we newly defined and estimated C-COI of CVD (ICD10 code: I60 - I69) and dementia (ICD10code: F01, F03, G30). C-COI consists of five parts; direct cost (medical), morbidity cost, mortality cost, direct cost (long term care (LTC)) and informal care cost (family’s burden). Direct cost (medical) is medical cost of each disease. Morbidity cost is opportunity cost for inpatient care and outpatient care. Mortality cost is measured as the loss of human capital (human capital method). These three costs are known as components of original cost of illness by Rice D. Direct cost (LTC) is long term care insurance benefits. Family’s burden is “unpaid care cost” by family, relatives and friends in-home and in-community (opportunity cost). We calculated such costs at 2013/2014 using Japanese official statistics.

Results: The total C-COI of CVD in Japan was about 6,177 billion JPY, the maximum was 621 billion JPY in Tokyo and the minimum was 33 billion JPY in Tottori (Tokyo/Tottori=18.8), whereas the total C-COI of dementia was 3,778 billion JPY, the maximum was 341 billion JPY in Tokyo and the minimum was 22 billion JPY in Tottori (Tokyo/Tottori=15.5). The C-COI per capita of CVD in Japan was about 48 thousand JPY, the maximum was 66 thousand JPY in Kagoshima and the minimum was 38 billion JPY in Saitama (Kagoshima/Saitama=1.7), whereas the total C-COI of dementia was 3,778 billion JPY, the maximum was 46 thousand JPY in Shimane and the minimum was 22 thousand JPY in Chiba (Shimane/Chiba=2.1).

Conclusion: We substantiated a method to calculate the social burden of medical care and LTC care for each prefecture using C-COI methods. In both diseases, a large difference was found in total costs per capita and components ratio between prefectures. The situations of social burden of diseases has diversity among prefectures. When estimating the future medical needs of each region, it is necessary to take each regional condition into account.