Accuracy of current clinical diagnosis in recreational drug-related attendance to the emergency department.

OBJECTIVE: To determine the accuracy of current clinical diagnosis in recreational drug-related attendances to emergency by blood analysis.

METHODS: A prospective convenience sample of 103 patients who attended hospital with suspected recreational drug-related presentations was collected. Doctors' clinical impression of drugs responsible for presentation was compared with a detailed forensic blood analysis for recreational drugs.

RESULTS: Among 103 samples, 80 (78%, 95% confidence intervals [CI] 70-86%) were found to have correct clinical suspicion of the recreational drug responsible for clinical presentation confirmed by laboratory analysis. Clinical diagnosis was most accurate for gamma-hydroxy butyrate (GHB) (sensitivity 97%, specificity 91%) and less accurate for amphetamines (sensitivity 61%, specificity 79%), alcohol (sensitivity 42%, specificity 84%) and opiates (sensitivity 46%, specificity 100%). Multiple drug ingestion was found in 70% (95% CI 61-79%) of samples. Sensitivity and specificity of clinical impression for prediction of multiple drug ingestion presence is 75% (95% CI 66-83%) and 85% (95% CI 78-92%), respectively.

CONCLUSION: Clinical diagnosis in recreational drug-related attendances to the ED was correct in most cases. Drugs, such as GHB, were the most accurately diagnosed. Inaccuracy in recognizing other drugs, like amphetamines, opiates and alcohol, occurs where a coingestant produces a more profound clinical picture. Multiple drug ingestion is a common scenario in recreational drug presentations to emergency.