Regulatory factors of medical care expenditures for older people in Japan--analysis based on secondary medical care areas in Hokkaido.

For the purpose of clarifying determinants of medical care expenditure for older people in Japan, we analyzed the data on medical care expenditure for older people in 21 secondary medical care areas in Hokkaido, the second largest island of Japan. The annual amount of medical expenditure per insured older person can be reduced into three components: annual number of medical care bills per insured older person days of hospitalization or visits per medical care bill and amount of medical expenditure per day and per insured older person. The 21 secondary medical care areas in Hokkaido showed large differences in per capita amount of both inpatient and outpatient medical expenditures for older people. Per capita inpatient medical expenditure for men and women correlated positively with the days of hospitalization per bill and the per capita number of inpatient medical care bills per year, but inversely with the per capita amount of expenditure per day of hospitalization. The same held true for outpatient medical expenditure for men, but for women outpatient medical expenditure correlated positively with all three components. Multiple regression analysis indicated the more powerful effects of medical care demand or supply on inpatient medical expenditure, on the other hand, not much powerful effects of every index were indicated on outpatient medical expenditure.