Evaluation of the triage system for emergency drugs-of-abuse testing in urine.

The Triage Panel for Drugs of Abuse (DOA) was evaluated for detection of phencyclidine (PCP), amphetamines (AMPH), opiates (OPI), tetrahydrocannabinol (THC), the cocaine metabolite benzoylecgonine (BE), and barbiturates (BARB) in urine. This assay was compared with Syva EMIT. The comparisons were conducted on 606 positive and 325 negative samples. When there was a sufficient volume of sample available for retesting, positive and negative samples with discordant results between these two screening assays were confirmed by quantitative gas chromatography/mass spectrometry (GC/MS). The percent agreement between the two assays for positive samples ranged from 93 to 100%. For negative samples, the agreement ranged from 95 to 100%. For AMPH, 19 out of 27 discordant samples of urine that were positive for EMIT and negative for Triage DOA contained total amphetamine and methamphetamine concentrations of less than 1000 ng/mL by GC/MS. For THC, seven urine samples that were negative for Triage DOA and positive for EMIT contained 9-carboxy THC concentrations at greater than 15 ng/mL by GC/MS. For BARB, three samples that were negative for Triage DOA and positive for EMIT contained barbiturates levels greater than 300 ng/mL. Two of these three samples contained phenobarbital below the concentration that produces a positive result for Triage DOA. For the majority of the urine samples studied, however, the Triage DOA produced identical results to a commercial-instrument-based immunoassay.