Rate of health insurance reimbursement and adherence to anti-hypertensive treatment among Japanese patients

Background: Although several studies have reported the effects of free medical care on compliance in patients with hypertension, no study has reported the effects of an economic incentive, such as subsidized medical costs, on compliance with medication protocol, in patients with hypertension. The unique characteristics of the Japanese health insurance system provide for a 10% decrease in the subsidy for medication immediately on retirement (approximately 60 years of age) for insured patients, and a 100% subsidy for insured patients who are 70 years of age or older. We examined the association between level of health insurance coverage and follow-up rate of medical treatment among Japanese patients with hypertension. Methods: The subjects, from throughout Japan, were patients with hypertension (n = 1236). The study was conducted in 1991. The odds of completing a 1-year treatment in relation to the rate of health insurance reimbursement were calculated using multiple logistic regression analysis. Results: We found the following. (1) Compared with the base group, the odds of completing a 1-year treatment increased to 2.62 or 2.51 in the group whose reimbursement rate was 100%. (2) Compared with the base group, the odds of completing a 1-year treatment was no larger than 1 in the group whose reimbursement rate had been 100% for more than 6 years ('76-'). (3) Compared with the base level, the odds of completing a 1-year treatment increased to 1-1.81 in the group whose liability decreased to 80%. Conclusion: Although the results imply that even a small economic incentive might be effective in securing a patient's compliance with anti-hypertensive medical treatment, the effect appear limited in both duration and magnitude.