The authors read the article “Accuracy of the DriveABLE cognitive assessment to determine cognitive fitness to drive” by Dr Dobbs, which appeared in the March issue of Canadian Family Physician (http://www.cfp.ca/content/59/3/e156.full.pdf+html), and disagree with his interpretation of the findings. Dr Dobbs’ conclusion that the DriveABLE In-Office cognitive assessment is highly accurate in identifying drivers with suspected or confirmed cognitive impairment who would pass or fail the DriveABLE On-Road Evaluation is based, incorrectly, on overall cell percentages. In his article, he stated the following: “For the total sample, only 1.7% of the patients who received an In-Office pass outcome received a mismatching DORE [DriveABLE On-Road Evaluation] outcome of fail. The errors for the fail out-come were somewhat higher but still low (5.6%).”Rather than presenting overall percentages, Dr Dobbs should have reported the actual cell counts and the row percentages, as these are far more relevant (a revised version of Table 1 is available from the corresponding author). The row percentages show that 62 of the 504 individuals who passed the In-Office assessment (12.3%) failed the On-Road test; and 204 of the 1474 who failed the In-Office assessment (13.8%) passed the On-Road test. These numbers are very different than the 1.7% and 5.6% presented in the article. (Author/publisher)
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