Evaluating the Utility of Dipstick Drug Screens as a Postmortem Triage Modality

Abstract

Urine dipsticks are an inexpensive, rapid tool for detecting common drugs of abuse (e.g., cocaine, oxycodone, methamphetamine, opiates, and benzodiazepines) in postmortem urine samples. For urine dipsticks to be useful as a triage modality, it is important that dipsticks have high diagnostic accuracy. We tested the performance of urine dipsticks as compared with toxicological analysis of postmortem blood as the gold standard for 198 cases for at least one of five common drugs of abuse during a six-month period at the Office of the Medical Examiner of Cook County, Illinois. Toxicological screening with enzyme-linked immunosorbent assay (ELISA) and confirmation with gas chromatography/mass spectrometry (GC/MS) were then performed on postmortem blood samples. The results were compared to calculate the sensitivity, specificity, positive predictive value, and negative predictive value of the urine dipstick screens. For cocaine (n=178), opiates (n=186), oxycodone (n=47), benzodiazepines (n=45), and methamphetamine (n=44), the sensitivity, specificity, positive predictive value, and negative predictive value of the urine dipsticks all exceeded 97%. Urine dipsticks are an accurate and reliable screening tool for drugs of abuse. This inexpensive screen may be used to triage cases to autopsy or external examination in cases where the differential includes natural disease versus drug-related death.