RÉSUMÉ
BACKGROUND: Hospital admissions for ambulatory care sensitive conditions (ACSCs), which are widely used as an indicator of poor access to primary care, can be used as an efficiency indicator of healthcare use in countries providing good access to health care. Korea, which has a national health insurance (NHI) system and a good supply of health care resources, is one such country. To quantify admission rates of ACSC and identify characteristics influencing variation in Korean health care institutions. METHODS: By using NHI claims data, we computed the mean ACSC admission rate for all institutions with ACSC admissions. RESULTS: The average ACSC admission rate for 4,461 institutions was 1.45%. Hospitals and clinics with inpatient beds showed larger variations in the ACSC admission rate (0%-87.9% and 0-99.6%, respectively) and a higher coefficient of variation (7.96 and 2.29) than general/tertiary care hospitals (0%-19.1%, 0.85). The regression analysis results indicate that the ACSC admission rate was significantly higher for hospitals than for clinics (β=0.986, p<0.05), and for private corporate institutions than public institutions (β=0.271, p<0.05). CONCLUSION: Substantial variations in ACSC admission rates could suggest the potential problem of inefficient use of healthcare resources. Since hospitals and private corporate institutions tend to increase ACSC admission rates, future health policy should focus on these types of institutions.