[The contributing factors to surplus medicine by long-term users of medical aid in Korea].

OBJECTIVES The amount of medical utilization by Medical Aid recipients was 3.7 times that of patients with Korean Medical Insurance. This study aims to describe the surplus medicine and the medication-related utilization, and to determine factors contributing to surplus medicine. METHODS Among those who used copayment-free Class I Medical Aid in 2005, 146,880 subjects who were >/=19 year-old and received >365 days medical treatment per year were studied with their case managers by conducting face-to-face interviews. The analytic methods were description, chi-square, t-tests, ANCOVA and multiple logistic regressions. RESULTS Most subjects were female (68.6%), the elderly (62.5%), and the separated (61.6%), had an elementary graduation or less (74.8%), and had disabilities (33.2%). The percentage of subjects with surplus medicine was 18.5%. However, the percentage of females, the elderly, those with non-disabilities, the separated, the uneducated, those with a very poor perceived health status and those with an economical burden for medical treatment was 19.3%, 18.9%, 19.0%, 19.3%, 19.0%, 20.2% and 24.3%, respectively. For subjects with surplus medicine, averages for the number of used pharmacies, the pharmacy-visit days and the medication costs were 4.6 drugstores, 34.9 days and approximately 1,124 thousand Won(\). These values were higher than those without surplus medicine (4.4 drugstores , 33.8 days, and Won(\)1,110 thousand, respectively). The odds ratios of the contributing factors to surplus medicine were female 1.11 (95% CI=1.07-1.14), the elderly 1.06 (95% CI=1.02-1.10), those with non-disabilities 1.08 (95% CI=1.05-1.12), the separated 1.14 (95% CI=1.10-1.18), the unmarried 1.12 (95% CI=1.07-1.18), the uneducated 1.03 (95% CI=1.01-1.08), those with a very poor perceived health status 1.04 (95% CI=1.01-1.08) and experiencing an economical burden for medical treatment 2.33 (95% CI=2.26-2.40). CONCLUSIONS 18.5% of subjects had surplus medicine with a higher mean of medication cost. Therefore, health education and health promotion programs to prevent surplus medicine and to improve the appropriate usage of medication are necessary.