NEW YORK (Reuters Health) – Simple tests performed during an office visit can help identify who can safely drive after a stroke, investigators from Belgium and the US report in the February 22 issue of Neurology.

They conducted a systematic review of 30 relevant studies on fitness-to-drive after stroke and a meta-analysis of 27 of the studies. In all of the studies, participants’ driving skills were tested in an on-road evaluation obtained about 9 months after the stroke. Participants also took in-office cognitive tests prior to their driving test.

Among a total of 1,728 participants, whose average age was 61 years, 938 (54%) passed the on-road evaluation.

According to a meta-analysis of the data, the best in-office cognitive tests to identify those individuals who are most likely to fail the on-road driving test are the Road Sign Recognition test, the Compass test, and the Trail Making Test B.

“Out of the 54 potential determinants of fitness-to-drive, these 3 tests were most predictive of driving performance as evaluated by an on-road test,” study investigator Dr. Hannes Devos, of Catholic University of Leuven, Belgium, noted in an e-mail to Reuters Health.

The Road Sign Recognition test assesses traffic knowledge and visual comprehension; the Compass task examines visual-perceptual and visual-spatial abilities and mental speed; and the Trail Making Test B measures visual-motor tracking and visual scanning abilities.

People who score below 8.5 out of 12 on the Road Sign Recognition test, below 25 out of 32 on the Compass test and take more than 90 seconds to finish the Trail Making Test are more likely to fail the on-road evaluation, the researchers report. The tests correctly classified 80 to 85 percent of the unsafe drivers. These individuals “should be referred for further on-road assessment,” the authors say.

Dr. Devos told Reuters Health that due to methodological reasons, they were not able to calculate the cumulative predictive accuracy of the three tests. “It may be that the predictive accuracy would even be higher.” Because the road sign recognition test was the most predictive test, “if I were to choose only one, I would recommend this test for use in clinical practice,” Dr. Devos said.

The researcher acknowledged that screening for fitness-to-drive is a delicate process for physicians. “Some physicians do not feel confident to screen for fitness-to-drive because they lack standardized tools that can be administered in the doctor’s office. They currently rely on a medical history and an interview with the patient and the next of kin regarding driving problems (and) often overestimate the actual driving skills of stroke drivers. A quick and objective screening in the doctor’s office can help to make more accurate decisions.”

The study also showed that patients’ clinical characteristics and motor symptoms did not predict on-road performance, which is not surprising, note the researchers, “considering the extensive range of in-vehicle adaptive devices available,” such as steering knobs that can be operated by one hand and left-foot accelerator pedals for people with limited use of the right leg.

Three out of four studies found no increased risk of being involved in an accident in people cleared to resume driving after stroke. However, they say there are “too few studies to conclude that stroke drivers who pass an on-road evaluation do not exhibit an increased risk of crashing.” They say further research is needed to determine predictors of accident proneness after stroke.

“Issues about screening for fitness-to-drive,” Dr. Devos mentioned, “do not only affect persons recovering from stroke, but also persons with neurodegenerative conditions such as Alzheimer Disease, Parkinson disease, and elderly persons with age-related cognitive decline.”

Neurology 2011;76:747-756.