title: Using Serial Trichotomization With Common Cognitive Tests to Screen for Fitness to Drive.
abstract: The aim of this study was to illustrate the use of serial trichotomization with five common tests of cognition to achieve greater precision in screening for fitness to drive.
  
  
  
  We collected data (using the Montreal Cognitive Assessment, Motor-Free Visual Perception Test, Clock-Drawing Test, Trail Making Test Part A and B [Trails B], and an on-road driving test) from 83 people referred for a driving evaluation. We identified cutpoints for 100% sensitivity and specificity for each test; the driving test was the gold standard. Using serial trichotomization, we classified drivers as either "Pass," "Fail," or "Indeterminate."
  
  
  
  Trails B had the best sensitivity and specificity (66.3% of participants correctly classified). After applying serial trichotomization, we correctly identified the driving test outcome for 78.3% of participants.
  
  
  
  A screening strategy using serial trichotomization of multiple test results may reduce uncertainty about fitness to drive.
authors.affiliation: Carrie Gibbons, MPH, is Research Coordinator, Centre for Applied Health Research, St. Joseph's Care Group, Thunder Bay, ON, Canada.
authors.forename: Carrie
authors.initials: C
authors.lastname: Gibbons
authors.affiliation: Nathan Smith, MPH, is Research Assistant, Centre for Research on Safe Driving, Lakehead University, Thunder Bay, ON, Canada.
authors.forename: Nathan
authors.initials: N
authors.lastname: Smith
authors.affiliation: Randy Middleton, MScOT, is Occupational Therapist, St. Joseph's Hospital, St. Joseph's Care Group, Thunder Bay, ON, Canada.
authors.forename: Randy
authors.initials: R
authors.lastname: Middleton
authors.affiliation: John Clack, MScOT, is Occupational Therapist, St. Joseph's Hospital, St. Joseph's Care Group, Thunder Bay, ON, Canada.
authors.forename: John
authors.initials: J
authors.lastname: Clack
authors.affiliation: Bruce Weaver, MSc, is Research Associate, Centre for Research on Safe Driving, Lakehead University, Thunder Bay, ON, Canada, and Assistant Professor, Northern Ontario School of Medicine, Thunder Bay, ON, Canada.
authors.forename: Bruce
authors.initials: B
authors.lastname: Weaver
authors.affiliation: Sacha Dubois, MPH, is Research Statistician, Centre for Applied Health Research, St. Joseph's Care Group, Thunder Bay, ON, Canada; Adjunct Professor, Lakehead University, Thunder Bay, ON, Canada; and Assistant Professor, Northern Ontario School of Medicine, Thunder Bay, ON, Canada.
authors.forename: Sacha
authors.initials: S
authors.lastname: Dubois
authors.affiliation: Michel Bédard, PhD, is Professor, Lakehead University and Northern Ontario School of Medicine, Thunder Bay, ON, Canada; Director, Centre for Research on Safe Driving, Lakehead University, Thunder Bay, ON, Canada; and Scientific Director, Centre for Applied Health Research, St. Joseph's Care Group, Thunder Bay, ON, Canada; mbedard@lakeheadu.ca.
authors.forename: Michel
authors.initials: M
authors.lastname: Bédard