Availability of urine toxicologic screening tests in the emergency department: focused on illegal drugs

Abstract

Purpose: In Korea, it is predicted that the proportion of drug abusers among patients visiting the emergency room will soon increase. Several emergency medical institutions in Korea are conducting field urine screening tests for poisoning. In this study, we investigated the characteristics and usefulness of urine toxicology screening tests. Methods: The medical records of patients with positive results for tetrahydrocannabinol and methamphetamine from urine toxicology screening tests at a tertiary university hospital from August 2016 to August 2019 were reviewed retrospectively. The subjects were classified into positive and false-positive groups, and their clinical characteristics were compared and analyzed. Results: Of the 2,026 patients surveyed, 823 patients (40.6%) tested positive for one or more drugs. Among them, 12 cases (0.6%) were positive for methamphetamine and 40 cases (2.0%) were positive for tetrahydrocannabinol. The positive and the false-positive rates for methamphetamine were 66.7% and 33.3%, respectively. The positive and the false-positive rates for tetrahydrocannabinol were 2.5% and 97.5%, respectively. Conclusion: Methamphetamine showed a relatively low false-positive rate in our study. Therefore, this test seemed to assist in diagnosing methamphetamine poisoning when considered together with the present illness and physical examination results. On the other hand, the high false-positive rate for tetrahydrocannabinol tests indicates that this test was unlikely to assist in diagnosing tetrahydrocannabinol poisoning. However, considering the growing trend of illegal drug abusers in Korea, it may still be useful as a diagnostic tool for identifying drug users.