Medical cost for disability: A longitudinal observation of national healthinsurance beneficiaries in Japan

OBJECTIVES: To measure the impact of disability on the use of medical care and its costs. DESIGN: A 1-year prospective cohort study of National Health Insurance bene ficiaries in a rural Japanese community. Their physical function was examin ed by the Medical Outcomes Study questionnaire at the end of 1994; medical care,and its costs were then monitored for 1 year. SETTING AND PARTICIPANTS: Participants were the 49,364 subjects, aged 40 to 79 years, who were beneficiaries of National Health Insurance and lived in the catchment area of Ohsaki Public Health Center, Miyagi, Japan. The subj ects were mainly farmers, self-employed persons, housewives, or pensioners. MEASUREMENTS: Medical care utilization (number of outpatient visits and day s of inpatient care) and the costs for each subject were obtained from Nati onal Health Insurance Claim History files. These measurements were collecte d from January to December 1995, and the relationship between physical func tioning levels and medical costs was analyzed. RESULTS: The medical costs per capita increased with poorer physical functi on. Medical costs among those with limitations in performing self-care incr eased by 4 times in men and 3 times in women compared with those with no fu nctional limitation. In this cohort, the 4.3% of the subjects who were depe ndent in self-care used 15% of the total inpatient days and 10% of the tota l medical costs. CONCLUSION: Treatment of patients with disability requires a huge amount of medical resources, There is an urgent need for cost-effective intervention programs for disability prevention, which could be offset against the cost for treating the disabled.