Medical expenditures of men with hypertension and/or a smoking habit: a 10-year follow-up study of National Health Insurance in Shiga, Japan.

Hypertension and smoking are major causes of disability and death, especially in the Asia-Pacific region, where there is a high prevalence of a combination of these two risk factors. We attempted to measure the medical expenditures of a Japanese male population with hypertension and/or a smoking habit over a 10-year period of follow-up. A cohort study was conducted that investigated the medical expenditures due to a smoking habit and/or hypertension during the decade of the 1990s using existing data on physical status and medical expenditures. The participants included 1708 community-dwelling Japanese men, aged 40-69 years, who were classified into the following four categories: 'neither smoking habit nor hypertension', 'smoking habit alone', 'hypertension alone' or 'both smoking habit and hypertension.' Hypertension was defined as a systolic blood pressure of > or =140 mm Hg, a diastolic blood pressure of > or =90 mm Hg or taking antihypertensive medications. In the study cohort, 24.9% had both a smoking habit and hypertension. During the 10-year follow-up period, participants with a smoking habit alone (18,444 Japanese yen per month), those with hypertension alone (21,252 yen per month) and those with both a smoking habit and hypertension (31,037 yen per month) had increased personal medical expenditures compared with those without a smoking habit and hypertension (17,418 yen per month). Similar differences were observed even after adjustment for other confounding factors (P<0.01). Japanese men with both a smoking habit and hypertension incurred higher medical expenditures compared with those without a smoking habit, hypertension or their combination.