Detection of hidden populations using illicit substances.
Journal of epidemiology and community health April 23, 2025 Shyh-Yuh Wei, Brian Meng-Hsun Li, Hsuan-Yun Hu et al. 1 citation
Hidden populations of people who use illicit drugs—those without arrest records—are much larger than official records suggest. In Taiwan, linking drug-related autopsy and police arrest data from 2010–2019 showed that for every registered (arrested) heroin user, there were 0.7 unregistered users; for methamphetamine, 2.2; for ecstasy, 14.8; for ketamine, 4.9; and for new psychoactive substances (NPS), 174.0. Unregistered individuals were younger, more often female, employed, and had higher blood alcohol levels. About 79% of polydrug use detected at autopsy occurred among unregistered individuals, and 10% had other substance use records differing from those found at death. The approach offers a way to estimate hidden populations, and clinicians should consider possible polydrug use even when single-substance tests are negative.