Pre–post study demonstrates increased discrepancy detection in methadone inventory tracking, indicating enhanced stock transparency through weight-based measurement.
Key Points
To develop and evaluate a novel weighing approach to improve the accuracy and management of methadone stock inventory.
Collected purchase, prescription, and inventory data across 8 drug addiction treatment centres in Tainan, Taiwan, from 2017 to 2022.
Implemented a novel weighing algorithm involving device calibration, weighing utensils and liquid before and after dispensation, and calculating consumed volume using measured weight and density.
Conducted descriptive pre–post comparisons of inventory surplus ratios between the baseline period (2017–2019) and the post-implementation period (2020–2022).
Total recorded inventory surplus across the 8 centres rose from 4.46 L pre-intervention to 17.77 L post-intervention.
Annual methadone inventory surplus ratios increased from 0.11%–0.13% before implementation to 0.20% in 2020, 0.74% in 2021, and 0.98% in 2022.