Which Patients Are Fit to Drive After a Stroke?

The pertinent issue may be not which patients are likely to fail a road test, but rather who should take the test in the first place.
What are the best clinical predictors of passing a road test after a stroke? To find out, investigators conducted a literature search for English language reports on outcome of a pass/fail road test after a stroke. The researchers identified 30 such studies, 27 of which provided sufficient data to be included in a meta-analysis. “Fitness-to-drive” data were analyzed for 1728 people; all had been active drivers before they had their strokes.
Of 54 measures of physical, visual, and cognitive function that were evaluated, only 5 (Cube Copy, Stroke Drivers Screening Assessment, Road Sign Recognition, the Compass task, and Trail Making Test part B) were clinically relevant (i.e., met the effect-size cutoff of >0.8) and had statistically significant P values. Road Sign Recognition, the Compass task, and the Trail Making Test were the best determinants of fitness to drive after a stroke. Motor deficits were not predictive, largely because vehicles can usually be outfitted to accommodate such limitations. Visual deficits were not predictive because any substantial visual impairment precluded being licensed to drive.
Road-test pass/fail rates varied enormously across the studies, suggesting wide variation in the road tests themselves, in the participant-selection criteria, or both. In four studies, fail rates were at least double the pass rates, perhaps because of extremely difficult road tests or nonstringent criteria for including participants. In six studies, pass rates were at least double the fail rates, perhaps because of easy road tests or selective inclusion criteria. In one instance, the pass rate was nearly 8 times the fail rate, likely attributable to in-depth screening before the road test.
Comment: The authors assert that “more than half of persons with stroke are fit to drive following a successful on-road examination.” This estimate does not account for the large number of patients who are never referred for a road test in the first place — either because of severe disabilities that clearly preclude safe driving or because of apparent recovery to prestroke function. The more effective the poststroke screening, the less the apparent need for road testing. Although several office-based tests were predictive of road-test performance, this study was not designed to answer the best screening tests to determine referral for road testing. Most physicians are not familiar with the office-based tests used in this study, so they should refer patients to specialists (e.g., occupational therapists) who are. Ultimately, clinicians should become adept at determining which of their patients should be referred for a road test.
— Germaine L. Odenheimer, MD