title: Effects of central nervous system drugs on driving: speed variability versus standard deviation of lateral position as outcome measure of the on-the-road driving test.
abstract: BACKGROUND
  The on-the-road driving test in normal traffic is used to examine the impact of drugs on driving performance. This paper compares the sensitivity of standard deviation of lateral position (SDLP) and SD speed in detecting driving impairment.
  
  
  METHODS
  A literature search was conducted to identify studies applying the on-the-road driving test, examining the effects of anxiolytics, antidepressants, antihistamines, and hypnotics. The proportion of comparisons (treatment versus placebo) where a significant impairment was detected with SDLP and SD speed was compared.
  
  
  RESULTS
  About 40% of 53 relevant papers did not report data on SD speed and/or SDLP. After placebo administration, the correlation between SDLP and SD speed was significant but did not explain much variance (r = 0.253, p = 0.0001). A significant correlation was found between ΔSDLP and ΔSD speed (treatment-placebo), explaining 48% of variance. When using SDLP as outcome measure, 67 significant treatment-placebo comparisons were found. Only 17 (25.4%) were significant when SD speed was used as outcome measure. Alternatively, for five treatment-placebo comparisons, a significant difference was found for SD speed but not for SDLP.
  
  
  CONCLUSIONS
  Standard deviation of lateral position is a more sensitive outcome measure to detect driving impairment than speed variability.
authors.forename: Joris C
authors.initials: JC
authors.lastname: Verster
authors.forename: Thomas
authors.initials: T
authors.lastname: Roth
mesh_terms: D001334:Automobile Driving; D002491:Central Nervous System Agents / Q000494:pharmacology*; D006801:Humans; D017063:Outcome Assessment, Health Care / Q000379:methods*; D011597:Psychomotor Performance / Q000187:drug effects
chemical_list: D002491:Central Nervous System Agents