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 DDS1, Drugtest 50001,
Drugwipe 5+1 and RapidSTAT1, 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% (RapidSTAT1), 82% (DDS1), 90% (Drugwipe 5+1) and 97%
(Drugtest 50001) for cocaine and 38% (DDS1), 47% (Drugwipe 5+1), 72% (RapidSTAT1) and 92%
(Drugtest 50001) for THC. Drugtest 5000 was the only kit showing an acceptable sensitivity for on-site
application. Only Drugtest 50001 and RapidSTAT1 could be evaluated for amphetamines and
methamphetamines: Drugtest 50001 showed a sensitivity of 100% in the case of amphetamines and 86%
for methamphetamines, while RapidSTAT1 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.
- DUID, Oral Fluid, On-site testing, kits evaluation