[A survey of self-medication practices and related factors in the general population: the Ohasama study]

Encouraging self-medication is expected to reduce healthcare costs. To assess the current situation of self-medication practices in the general population, we conducted a questionnaire survey regarding the use of over-the-counter (OTC) medications or dietary supplements in 1008 participants (37% men; mean age, 64±13 years) from Ohasama, a rural Japanese community. A total of 519 (52%) participants used OTC medications or dietary supplements, with common cold medication (36%) and supplements (28%) such as shark cartilage products representing the most common choices. Stepwise logistic regression showed female gender, a higher frequency of visits from a household medicine kit distributor, dyslipidemia, and lower home systolic blood pressure levels as predictors for the use of such materials (chi-square values: 25.3, 12.6, 7.0, and 4.6, respectively; all p<0.03). Stratifying the participants according to the use of antihypertensive treatment showed a negative association between systolic blood pressure and the use of OTC medications or supplements only in participants being treated for hypertension. These results suggest that although the adoption rate of self-medication in Japan can be increased in rural areas, it may remain lower in urban areas. The present study clarifies the factors associated with the use of OTC medications or dietary supplements and indicates that appropriate self-medication practices might improve the control of hypertension, particularly in patients undergoing antihypertensive treatment.