Concurrent validity of the stroke drivers screening assessment

Abstract

Radford KA, Lincoln NB. Concurrent validity of the Stroke Drivers Screening Assessment. Arch Phys Med Rehabil 2004;85:324–8. Objective To determine the concurrent validity of the Stroke Drivers Screening Assessment (SDSA). Design Comparison of the SDSA with criterion standards. Setting Subjects’ homes in the community in the United Kingdom. Participants Ninety-three stroke patients (age range, 22–83y) who were referred for assessment of fitness to drive or who had been driving before their stroke. Participants were assessed a median of 5 months poststroke. Interventions Not applicable. Main outcome measures Patients were assessed on the SDSA and tests of visuospatial ability (Visual Object and Space Perception [VOSP] Battery), executive abilities (Stroop Neuropsychological Screening Test, Trail-Making Test [TMT], Cognitive Estimates Test [CET]), and visual memory (Recognition Memory Tests [RMT], Verbal Descriptions of Road Signs [VDRS]). Results The SDSA subtests all correlated significantly with the Stroop test ( P<.001) and TMT ( P<.001), which suggests that they measure executive abilities and attention. The SDSA Dot Cancellation (DC) also correlated significantly with the VDRS ( P<.01). The SDSA Square Matrices (SM) test correlated significantly with the VOSP cube analysis ( P≤.01) and the RMT faces subtest ( P<.001), which suggests that the SM test also measures visuospatial abilities and visual memory. The SDSA Road Sign Recognition (RSR) test also correlated significantly with the VOSP cube analysis ( P<.05), which suggests that the RSR test also measures visuospatial abilities. Factor analysis produced a 2-factor solution with DC time, SM compass, and RSR all loading on factor 1, together with the Stroop and TMT. This factor was interpreted as “executive abilities and attention.” The RMT faces subtest and CET loaded onto a second factor. Conclusions The SDSA seems to measure predominantly attention and executive abilities, which have previously been shown to be important determinants of safety to drive. This may account for the high predictive validity of the SDSA.