A Study Comparing Self-Reported Drugs and Results of An Immunoassay Test in Serum Samples in Patients Presenting to The Emergency Department with Acute Recreational Drug

There is no consensus on the usefulness of toxicological analysis in the management of cases presenting to the Emergency Department (ED) with acute recreational toxicity. While in some centers urine samples are routinely analyzed, in others management is based on clinical interpretation and patient self-report on the drug(s) used. Most of the studies that investigated the role of toxicological analysis in this cohort have used urine for the drug testing. The aim of this study was to compare the drug(s) detected in blood samples analyzed by immunoassay (IA) with those self-reported by patients presenting to the ED with acute recreational drug toxicity. The data were collected from self-reported drug(s) in patients presenting to the ED with acute recreational drug toxicity and compared to the results of a serum Immunoassay which includes 20 different tests. There was weak agreement (kappa 0.2 - 0.5) with significant disagreement between IA self-report for most of the drug assays, including cocaine, pregabalin, cannabis, and methadone. The poorest agreement was seen for synthetic cannabinoids (kappa 0.04) and benzodiazepines (kappa 0.13). The only exceptions with good agreement and insignificant disagreement between self-report and IA were methamphetamines (kappa = 0.65) and opiates (kappa = 0.60). Poor agreement existed between the IA test results in blood and the self-reported data. Further studies comparing IA/self-report data to a gold-standard confirmatory mass spectrometry (MS)-based test are required to definitively address the role of analytical screening in the assessment of patients with acute recreational drug toxicity.