National trends in antimicrobial consumption in Nepal, 2016-2023: an ecological analysis

To characterize class-specific national antimicrobial consumption patterns in Nepal from 2016 to 2023 and explore monotonic and linear temporal patterns, differences between the 2016-2019 and 2020-2023 periods, and the influence of selected high-consumption years.

We conducted a retrospective ecological analysis of five antimicrobial classes using annual national consumption expressed as Defined Daily Doses per 1,000 inhabitants per day (DID). Descriptive statistics summarized consumption; Mann-Kendall tests and linear regression explored temporal patterns; an exploratory period comparison assessed 2016-2019 versus 2020-2023; and sensitivity analyses assessed the influence of selected years.

Antibacterial agents had the highest mean consumption at 48.6 defined daily doses per 1,000 inhabitants per day (DID). Considerable year-to-year variability was observed across antimicrobial classes, with limited evidence of sustained temporal trends over the short observation period. Anti-tuberculosis drug consumption showed evidence of an upward monotonic pattern in the Mann-Kendall analysis. However, this finding was not supported by a statistically clear linear trend and was sensitive to exclusion of the 2023 value. Exploratory comparisons of the 2016-2019 and 2020-2023 period showed imprecisely estimated differences in antibacterial and antifungal consumption.

National antimicrobial consumption in Nepal showed substantial class-specific and year-to-year variation during 2016-2023. The short time series limits inference regarding sustained long-term trends, and the apparent upward pattern in anti-tuberculosis drug consumption should be interpreted cautiously.