Changes in antibiotic consumption patterns after the implementation of the National Action Plan according to the Access, Watch, Reserve (AWaRe) classification system

•Antimicrobial resistance (AMR) constitutes a major threat to public health worldwide.•The World Health Organization recommends administering antibiotics only when necessary.•The Korean government published the first National Action Plan (NAP) in August 2016.•No other studies have examined the effects of the NAP on AMR in South Korea.•The implementation of the NAP was a factor in antibiotic consumption reduction in Korea. The Korean government published the first National Action Plan (NAP) on antimicrobial resistance (AMR) in August 2016, followed by a second plan in November 2021. The objective of this study was to analyze changes in antibiotic use patterns after the implementation of the NAP in South Korea. We analyzed National Health Insurance claims data for hospitals and clinics from January 2011 to December 2020. Consumption was measured using a defined daily dose per 1000 inhabitants per day (DID). We analyzed data for each year, dimension, and category of the Access, Watch, Reserve classification system by the World Health Organization. Monthly inpatient and outpatient antibiotic use were calculated, and an interrupted time-series (ITS) analysis to assess the trend in antibiotic use was conducted. The consumption of antibiotics increased from 25.78 DID in 2011 to 29.06 DID in 2016, then decreased in 2017 after the implementation of the NAP on AMR. The watch group showed a temporal decrease after the implementation of the NAP; however, these figures increased until 2019, and the reserve group showed a downward trend beginning in 2017. According to the ITS analysis, the level (β2) and the slope of the trend (β3) of total antibiotic use decreased by 0.17 and 0.001, respectively. After implementation of the NAP, antibiotic use was reduced from 7.18 DID in 2016 to 4.84 DID in 2017 for amoxicillin and beta-lactamase inhibitors, 0.86 DID to 0.70 DID for ciprofloxacin, and 0.66 DID to0.66 DID for levofloxacin. After the implementation of the NAP in South Korea, antibiotic use in terms of total antibiotics and fluoroquinolone in the watch and reserve groups decreased. Further policies to improve the use of antibiotics in the watch and reserve groups are needed.