title: The trail making test as a screening instrument for driving performance in older drivers; a translational research.
abstract: BACKGROUND
  In many countries, primary care physicians determine whether or not older drivers are fit to drive. Little, however, is known regarding the effects of cognitive decline on driving performance and the means to detect it. This study explores to what extent the trail making test (TMT) can provide indications to clinicians about their older patients' on-road driving performance in the context of cognitive decline.
  
  
  METHODS
  This translational study was nested within a cohort study and an exploratory psychophysics study. The target population of interest was constituted of older drivers in the absence of important cognitive or physical disorders. We therefore recruited and tested 404 home-dwelling drivers, aged 70 years or more and in possession of valid drivers' licenses, who volunteered to participate in a driving refresher course. Forty-five drivers also agreed to undergo further testing at our lab. On-road driving performance was evaluated by instructors during a 45 minute validated open-road circuit. Drivers were classified as either being excellent, good, moderate, or poor depending on their score on a standardized evaluation of on-road driving performance.
  
  
  RESULTS
  The area under the receiver operator curve for detecting poorly performing drivers was 0.668 (CI95% 0.558 to 0.778) for the TMT-A, and 0.662 (CI95% 0.542 to 0.783) for the TMT-B. TMT was related to contrast sensitivity, motion direction, orientation discrimination, working memory, verbal fluency, and literacy. Older patients with a TMT-A ≥ 54 seconds or a TMT-B ≥ 150 seconds have a threefold (CI95% 1.3 to 7.0) increased risk of performing poorly during the on-road evaluation. TMT had a sensitivity of 63.6%, a specificity of 64.9%, a positive predictive value of 9.5%, and a negative predictive value of 96.9%.
  
  
  CONCLUSIONS
  In screening settings, the TMT would have clinicians uselessly consider driving cessation in nine drivers out of ten. Given the important negative impact this could have on older drivers, this study confirms the TMT not to be specific enough for clinicians to justify driving cessation without complementary investigations on driving behaviors.
authors.affiliation: Traffic Medicine and Psychology Unit, University Center of Legal Medicine, Lausanne-Geneva, University Hospital of Lausanne, Rue Saint-Martin 26, 1005 Lausanne, Switzerland. paul.vaucher@gmail.com.
authors.forename: Paul
authors.initials: P
authors.lastname: Vaucher
authors.forename: Daniela
authors.initials: D
authors.lastname: Herzig
authors.forename: Isabel
authors.initials: I
authors.lastname: Cardoso
authors.forename: Michael H
authors.initials: MH
authors.lastname: Herzog
authors.forename: Patrice
authors.initials: P
authors.lastname: Mangin
authors.forename: Bernard
authors.initials: B
authors.lastname: Favrat
mesh_terms: D000063:Accidents, Traffic / Q000517:prevention & control*; D000367:Age Factors; D000368:Aged; D000375:Aging / Q000523:psychology*; D001334:Automobile Driving / Q000523:psychology*; D003072:Cognition Disorders; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D011237:Predictive Value of Tests; D012372:ROC Curve; D015203:Reproducibility of Results; D012189:Retrospective Studies; D018570:Risk Assessment / Q000379:methods*; D013997:Time Factors; D014145:Trail Making Test; D057170:Translational Research, Biomedical / Q000379:methods*