Overlapping Medication Associated with Healthcare Switching among Korean Elderly Diabetic Patients

This study was performed to describe the patterns of healthcare switching with overlapping use of anti-diabetic medication in the elderly using the Korea Health Insurance Review and Assessment Service's claims data. The study subjects were ambulatory elderly diabetic patients (ICD-10, E10-14) receiving at least one oral anti-diabetic drug or insulin, and visiting healthcare facilities more than two times between January and December 2005. A total of 457,975 elderly diabetic ambulatory care patients were identified. The mean of visiting frequencies was 9.0 (+/- 3.6) and switching frequencies was 1.5 (+/- 0.8) during 2005. Switching group consisted of 33% of total study subject. Healthcare switching was common in female patients who were older, and had treated polytherapy more in rural areas. The movement among primary care medical services was very common among the patients in the switching group (52.6%). A statistically significant correlation was observed between the healthcare switching and concomitant drug use (rho = 0.96), and overlapping days (rho = 0.57). The use of overlapping anti-diabetic medication increased with the extent of healthcare switching. Further, frequent switching of healthcare between primary clinics was observed. Efforts should be made to establish continuity for the elderly diabetic patients with the identification of frequent switching with overlapping medication.