Trend of antibiotics usage for acute pyelonephritis in Korea based on national health insurance data 2010-2014

Background: The objective of this study is to describe the changes in prescribing practices of antibiotics to treat acute pyelonephritis (APN) in Korea. Methods: The claim data base of the Health Insurance Review and Assessment Service in Korea was used to select patients with ICD-10 codes N10 (acute tubulo-interstitial nephritis) or N12 (tubulo-interstitial nephritis, not specified as acute nor chronic) as the primary discharge diagnosis during 2010-2014. Consumption of each class of antibiotics was converted to Defined Daily Dose (DDD)/event. Results: Throughout the five-year period, the average antibiotic consumption were 11.3 DDD per inpatient event and 6.0 DDD per outpatient event. The annual average antibiotic consumption increased for inpatients (P = 0.002), but remained stable for outpatients (P = 0.066). The use of parenteral antibiotics increased for inpatients (P < 0.001), but decreased for outpatients (P = 0.017). As for the the antibiotic classes, 3^rd generation cephalosporins (3^rd CEPs) was the most commonly prescribed (41.4%) for inpatients, followed by fluoroquinolones (FQs) (28.5%); for outpatient, FQs (54.8%) was the most commonly prescribed, followed by 3^rd CEPs (13.1%). The use of 3^rd CEPs (P < 0.001), beta-lactam/beta-lactamase inhibitors (P = 0.007), and carbapenems (P < 0.001) increased substantially for the treatment of hospitalized APN patients. In particular, carbapenems use increased 3.1-fold over the 5 years. Conclusions: Prescription of broad-spectrum antibiotics increased much for the treatment of APN in Korea during 2010-2014.