Evaluation of four oral fluid devices (DDS®, Drugtest 5000®, Drugwipe 5+® and RapidSTAT®) for on-site monitoring drugged driving in comparison with UHPLC-MS/MS analysis

New Italian legislation on driving under the influence of drugs considers oral fluid (OF) as a possible alternative drug testing matrix. On this basis, the present research was carried out to evaluate the applicability of four commercial on-site OF drug screening devices, namely DDS (R), Drugtest 5000 (R), Drugwipe 5+(R) and RapidSTAT (R), in a real operative context. Preliminarily trained police officers tested randomly stopped drivers with two different kits side-by-side during roadside patrols. A central laboratory confirmed on-site kits' results by UHPLC-MS/MS analysis of the saliva specimen remaining after the screening analysis. 1025 drivers were submitted to the OF tests: 11.6% were positive for cocaine and metabolites, 11.1% for THC, 6% for amphetamines and amphetamine-type designer drugs and 2.3% for ketamine. The sensitivities of the kits were 81% (RapidSTAT (R)), 82% (DDS (R)), 90% (Drugwipe 5+(R)) and 97% (Drugtest 5000 (R)) for cocaine and 38% (DDS (R)), 47% (Drugwipe 5+(R)), 72% (RapidSTAT (R)) and 92% (Drugtest 5000 (R)) for THC. Drugtest 5000 was the only kit showing an acceptable sensitivity for on-site application. Only Drugtest 5000 (R) and RapidSTAT (R) could be evaluated for amphetamines and methamphetamines: Drugtest 5000 (R) showed a sensitivity of 100% in the case of amphetamines and 86% for methamphetamines, while RapidSTAT (R) 90% and 76% respectively. Nowadays, ketamine is not included in the target analytes of any on-site devices, but it was systematically included in the UHPLC-MS/MS confirmatory analysis. To ensure adequate reliability, MS confirmation of on-site OF screening tests is anyway always necessary, due to the presence of a significant number of false positive results even when using the commercial kit with the best performance. (C) 2012 Elsevier Ireland Ltd. All rights reserved.