Using Serial Trichotomization With Common Cognitive Tests to Screen for Fitness to Drive

Carrie Gibbons; Nathan Smith; Randy Middleton; John Clack; Bruce Weaver; Sacha Dubois; Michel Bédard

doi:10.5014/ajot.2017.019695

Using Serial Trichotomization With Common Cognitive Tests to Screen for Fitness to Drive

Am J Occup Ther. 2017 Mar/Apr;71(2):7102260010p1-7102260010p8. doi: 10.5014/ajot.2017.019695.

Authors

Carrie Gibbons¹, Nathan Smith², Randy Middleton³, John Clack⁴, Bruce Weaver⁵, Sacha Dubois⁶, Michel Bédard⁷

Affiliations

¹ Carrie Gibbons, MPH, is Research Coordinator, Centre for Applied Health Research, St. Joseph's Care Group, Thunder Bay, ON, Canada.
² Nathan Smith, MPH, is Research Assistant, Centre for Research on Safe Driving, Lakehead University, Thunder Bay, ON, Canada.
³ Randy Middleton, MScOT, is Occupational Therapist, St. Joseph's Hospital, St. Joseph's Care Group, Thunder Bay, ON, Canada.
⁴ John Clack, MScOT, is Occupational Therapist, St. Joseph's Hospital, St. Joseph's Care Group, Thunder Bay, ON, Canada.
⁵ 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.
⁶ 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.
⁷ 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.

PMID: 28218592
DOI: 10.5014/ajot.2017.019695

Abstract

Objective: 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.

Method: 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."

Results: 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.

Conclusion: A screening strategy using serial trichotomization of multiple test results may reduce uncertainty about fitness to drive.