Decline in Antimicrobial Consumption and Stagnation in Reducing Disease Burden due to Antimicrobial Resistance in Japan.

introductionAntimicrobial resistance (AMR) is a major global health threat. While antimicrobial consumption (AMC) in Japan substantially decreased after implementation of the AMR National Action Plan, the disease burden due to AMR seems to be unchanged. The main objective of this study is to examine the relationship between AMC and the disease burden due to AMR in Japan.

methodsWe estimated the annual population-standardized AMC from 2015 to 2021 using defined daily doses (DDDs) per 1000 inhabitants per day (DIDs) and the disease burden due to bloodstream infections caused by nine major antimicrobial-resistant bacteria (AMR-BSIs) from 2015 to 2021 using disability-adjusted life years (DALYs). We then examined the correlation between AMC and DALYs using Spearman's rank correlation coefficient and cross-correlation function. Spearman's [Formula: see text] > 0.7 was considered to indicate a strong correlation.

resultsThe sales amounts of third-generation cephalosporins, fluoroquinolones, and macrolides were 3.82 DIDs, 2.71 DIDs, and 4.59 DIDs, respectively, in 2015, but 2.11, 1.48, and 2.72 in 2021. This corresponded to reductions of 44.8%, 45.4%, and 40.7% during the study period. DALYs due to AMR-BSIs were 164.7 per 100,000 population in 2015 but 195.2 per 100,000 in 2021. Spearman's rank correlation coefficients between AMC and DALYs were - 0.37 (total antibiotics), - 0.50 (oral antibiotics), - 0.43 (third-generation cephalosporins), - 0.5 (fluoroquin,olones) and - 0.5 (macrolides). No obvious cross-correlations were found.

conclusionsOur results reveal that changes in AMC are not associated with DALYs caused by AMR-BSIs. AMR countermeasures besides efforts to reduce inappropriate AMC might be necessary to mitigate the disease burden due to AMR.