Citation

Jongen S, Vermeeren A, van der Sluiszen NN, Schumacher MB, Theunissen EL, Kuypers KP, Vuurman EF, Ramaekers JG. Psychopharmacology 2017; 234(5): 837-844.

Affiliation

Department of Neuropsychology and Psychopharmacology, Faculty of Psychology and Neuroscience, Maastricht University, Universiteitssingel 40, 6200 MD, Maastricht, The Netherlands.

Copyright

(Copyright © 2017, Holtzbrinck Springer Nature Publishing Group)

DOI

10.1007/s00213-016-4519-z

PMID

28070617

Abstract

INTRODUCTION: The on-the-road highway driving test is generally regarded as a gold standard for assessing drug-induced driving impairment. The primary outcome measure is the standard deviation of lateral position (SDLP), a measure of road tracking error or "weaving". The test has been calibrated for incremental doses of alcohol almost 30 years ago in order to define the impact of drug-induced impairment in terms of blood alcohol concentration (BAC) equivalents. Drug-induced changes in SDLP exceeding 2.4 cm have been evaluated as clinically relevant ever since. The present analysis was conducted to assess the robustness of the alcohol effect in a range of on-the-road driving studies which have been conducted since the initial alcohol calibration study.

METHODS: The present study pooled data of 182 participants from nine placebo-controlled crossover studies who performed the highway driving test, while their BAC was at or just below the legal limit for drivers (i.e., 0.5 g/L).

RESULTS: Overall, mean SDLP increased with 2.5 cm (95% CI 2.0-2.9 cm). Equivalence testing showed that the clinical relevance criterion value of 2.4 cm fell well within the 95% CI in each individual study. Gender did not affect alcohol-induced changes in SDLP.

DISCUSSION: These results demonstrate the robustness and validity of the clinical relevance criterion for SDLP as measured during on-the-road driving.

Language: en