Assessment of the Contribution to Drug Impaired Driving from Emerging and Undertested Drugs

Impaired driving is an increasing problem in the United States and presents a public health and public safety concern. The extent, nature, concentrations, and prevalence with which impairing substances contribute most to cases of driving under the influence of drugs (DUID) is poorly understood, due to a lack of standardization of methods. Since 2007, the National Safety Council has promoted standardization of testing scope and analytical cutoffs for investigation of impaired driving cases and traffic fatalities, which has contributed to more consistency in testing practices. In the most recently published recommendations (2017), only 35 drugs and metabolites are included in the primary (Tier I) scope. The NSC identified a second list of drugs (Tier II) with significant impairing potential but whose prevalence or contribution is not well understood. Tier II includes emerging NPS and prescription drugs. Because most laboratories test only for Tier I drugs, there is a lack of information available on which Tier II substances are contributing to drug-impaired driving cases and fatal crashes. We propose performing expanded testing for both Tier I and Tier II drugs in blood samples from 4,400 DUID cases to include analysis of emerging NPS, such as emerging opioids and synthetic cannabinoids, in addition to other impairing substances such as central nervous system stimulants, depressants, narcotic analgesics, and dissociatives. We selected n=4,400 cases to be able to detect the prevalence of low-frequency positives. Samples will be provided by our collaborator, NMS Labs, and will be initially screened there using immunoassay for Tier I drugs. The CFSRE will perform LCQTOF testing for the remaining Tier II drugs and other substances, using a scope of 850 therapeutic, abused, and emerging drugs. We will also develop and validate quantitative confirmatory methods for those emergent and Tier II drugs that screen positive. This will allow an estimate of the frequency with which additional drugs contribute to the DUID problem. Additionally, the proposal will collect drug recognition expert (DRE) assessment data from a subset of these cases in which Tier II or emergent drugs are detected, to assess the signs and symptoms according to the DRE matrix. The study design will include a five-year retrospective review of drug data for over 50 Tier I and Tier II drugs in over 20,000 drug-impaired driving cases. This proposal will significantly contribute to addressing the DUID problem by increasing awareness of less commonly tested-for drugs, publishing methods for their confirmation and quantitation, and providing interpretive reference data to assist with impaired driving casework. Note: This project contains a research and/or development component, as defined in applicable law, and complies with Part 200 Uniform Requirements - 2 CFR 200.210(a)(14). CA/NCF