Nationwide study of outpatient oral antimicrobial utilization patterns for children in Japan (2013-2016)

Antimicrobial resistance (AMR) is a major multinational public health concern. The Japanese government set goals in its AMR action plan to reduce use of oral cephalosporins, macrolides, and quinolones by half between 2013 and 2020. We aimed to evaluate antimicrobial use in children in Japan by observing prescription patterns as an interim assessment of the national AMR action plan.

Using the national health claims database, we retrospectively analyzed all oral antimicrobials dispensed from outpatient pharmacies in Japan to children under 15 years old from 2013 to 2016 by age, prefecture, type of antimicrobial, and year. Data were presented as days of therapy (DOTs) per 1000 pediatric inhabitants per day (DOTs/PID). The χ² test for trends was performed to evaluate annual changes in DOTs/PID overall as well as within each stratum.

A total of 721,627,553 oral antimicrobial DOTs were identified during 2013-2016. No statistically significant changes were observed in total antimicrobial use in children (2013: 28.54 DOTs/PID; 2016: 28.70 DOTs/PID; P_trend = 0.25) and amount of cephalosporins, macrolides, and quinolones prescribed. Prescription rates of all antimicrobials were highest among children 1-5 years old, peaking at 1 year old. Targeted antimicrobials for the AMR action plan showed similar distribution by age.

The amount of antimicrobials prescribed to children in Japan is not decreasing. Overall antimicrobial prescriptions, as well as prescriptions of cephalosporins, macrolides, and quinolones, were most prevalent in children ≤5 years old. Rigorous antimicrobial stewardship interventions targeting infants and younger children are necessary.