Depression, Obstructive Sleep Apnea and Cognitive Impairment (DOC) Screen Completion Time Reflects Executive Function, Speed of Processing and Fluency.

BACKGROUND

The depression, obstructive sleep apnea and cognitive impairment (DOC) screen assesses three post-stroke comorbidities, but additional information may be gained from the time to complete the screen. Cognitive screening completion time is rarely used as an outcome measure.

OBJECTIVE

To assess DOC screen completion time as a predictor of cognitive impairment in stroke/transient ischemic attack clinics.

METHODS

Consecutive English-speaking stroke prevention clinic patients consented to undergo screening and neuropsychological testing (n = 437). DOC screen scores and times were compared to scores on the NINDS-CSC battery using multiple linear regression (controlling for age, sex, education and stroke severity) and receiver operating characteristic (ROC) curve analysis.

RESULTS

Completion time for the DOC screen was 3.8 ± 1.3 minutes. After accounting for covariates, the completion time was a significant predictor of the speed of processing (p = 0.002, 95% CI: -0.016 to -0.004), verbal fluency (p < 0.001, CI: -0.012 to -0.006) and executive function (p = 0.004, CI: -0.006 to -0.001), but not memory. Completion time above 5.5 minutes was associated with a high likelihood of impairment on executive and speed of processing tasks (likelihood ratios 3.9-5.2).

CONCLUSIONS

DOC screen completion time is easy to collect in routine care. People needing over 5.5 minutes to be screened likely have deficits in executive functioning and speed of processing - areas commonly impaired, but challenging to screen for, after stroke. DOC screen time provides a simple, feasible approach to assess these under-identified cognitive impairments.