Exploring the Predictive Validity of Drug Evaluation and Classification Program Evaluations

The objective of this study was to determine which combinations of drug-related signs and symptoms from the Drug Evaluation and Classification (DEC) protocol most efficiently and effectively predict the drug category or combination used by the subject. A sample of 2,261 DEC evaluations conducted on suspected drug-impaired drivers was obtained from 11 States. The sample included cases that involved specific drug categories and two-drug combinations that are commonly encountered by drug recognition experts (DREs). To assess the signs and symptoms from the DEC evaluation that best predict the drug category or drug combination used by suspected drug-impaired drivers, a series of statistical analyses was conducted. This study also examined how effectively the set of drug-related measures from the DEC procedure could distinguish drug-positive from drug-negative cases for two common drug categories (cannabis and central nervous system (CNS) depressants) and the relative importance of clinical, behavioral and observational measures in predicting drug categories responsible for impairment. Thirteen drug-related indicators were found to significantly contribute to the prediction of drug category; 12 indicators contributed significantly to the prediction of drug combinations. Additionally, indicators related to the appearance and physiological response of the eye contributed the most to the prediction of both single drug categories and drug combinations, followed closely by clinical indicators, and performance on the psychophysical tests. A qualitative analysis of cases ruled out for medical reasons revealed that the subjects were older than in other cases, were more likely to have been involved in a crash, and were more likely to report being diabetic. A variety of medical conditions and injuries were considered to have possibly influenced the evaluation or rendered the subject incapable of performing the tests.

• Record URL:
  https://rosap.ntl.bts.gov/view/dot/55937
• Corporate Authors:

  Canadian Center on Substance Abuse

  Ottawa, Ontario  Canada 

  National Highway Traffic Safety Administration

  Office of Behavioral Safety Research
  1200 New Jersey Avenue SE
  Washington, DC  United States  20590
• Authors:
  • Porath-Waller, Amy
  • Beirness, Doug
  • Smither, Dereece
• Publication Date: 2021-5

Language

• English

Media Info

• Media Type: Digital/other
• Edition: Final Report
• Features: Appendices; Figures; References; Tables;
• Pagination: 99p

Subject/Index Terms

• TRT Terms: Classification; Diseases and medical conditions; Drug effects; Drugged drivers; Drugs; Statistical analysis
• Identifier Terms: Drug Evaluation and Classification Program
• Subject Areas: Highways; Safety and Human Factors;

Filing Info

• Accession Number: 01774590
• Record Type: Publication
• Report/Paper Numbers: DOT HS 812 959
• Contract Numbers: DTNH22-10-C-00186
• Files: HSL, NTL, TRIS, ATRI, USDOT
• Created Date: Jun 22 2021 2:22PM