Incremental validity of brief and abbreviated neuropsychological tests toward predicting functional outcomes in multiple sclerosis.

Objective: This study examined the relationships among functional outcomes and performance on standard-length and abbreviated cognitive screening measures for multiple sclerosis (MS).

Method: 72 adults with MS underwent neurological examination and cognitive screening. They completed standard-length and abbreviated versions of tests from the Minimal Assessment of Cognitive Function in MS (MACFIMS), the abbreviated aMACFIMS, and the Brief International Cognitive Assessment for MS (BICAMS). Functional outcomes included neurological disability, physical and psychological dysfunction, and employment status.

Results: Concordance of impairment classifications was examined between standard-length and abbreviated tests using logistic regression and ROC curve analyses. Overall, the abbreviated test versions showed a broad range of concordance with impairment classifications made using the full-length tests. Processing speed was the strongest correlate of neurological disability and employment status; immediate recall was the strongest predictor of subjective physical dysfunction. Test performance provided unique value toward predicting neurological disability and employment status, but not physical and psychological dysfunction.

Conclusions: The findings replicate some support for abbreviated tests in MS assessment, although caveats regarding loss of validity associated with abbreviation remain. The findings extend prior research showing that abbreviated tests of processing speed and immediate recall can provide unique predictive information regarding objective functional outcomes.