Multiple Sclerosis, Employment, Cognitive Profile and Cognitive Testing: Predictability of SDMT and Computerized Cognitive Testing

Background: Cognitive impairment is common in people with MS (pwMS). Routine cognitive screening in MS care is not common. Unemployment is common in pwMS. Employment status may be affected by cognitive impairment, not apparent by EDSS. MS impacts cognition domains differently in pwMS. Easily available utilized objective cognitive screens are needed to evaluate cognition in MS independent of EDSS or MRI. SDMT, is not commonly used in routine MS care. SDMT as a single score cognitive measure does not provide information about individual cognitive domains or the presence/degree of impairment in multiple domains. Computerized cognitive screening tools provide scores for individual cognitive domains.

Objectives: To explore the predictability and effect size between SDMT and NeuroTrax computerized cognitive testing (NT-CCT) domains pwMS who self-report employment status.

Methods: Retrospective review pwMS referred for screening cognitive testing in the course of routine clinical care evaluated with both the oral version of SDMT and NT-CCT on the same day.

Results: 113 MS patients mean age 48.9±11.3yrs, 85% female. Standardized SDMT score (Centofani, 1975 age norms) significantly (p's<.001) correlated with NT-CCT Global Cognitive Score (GCS; r=.64), and executive function r=.60. Predicting employment status, SDMT and NeuroTrax GCS predict employment status (p<.001). The effect size (Cohen's d) of the NT-CCT GCS d=.83, and SDMT d=.70. NT-CCT Executive Function index d=.87.  The NeuroTrax Catch Game (scores standardized for age and education), overall score predicted employment p<0.001, d=.92.   Unemployed PwMS NT-CCT cognitive domain index scores >1SD below average for cognitively healthy age and education norms, 0 index scores (>1SD below): 34% unemployed, 2 index scores: 69%, 3 or more index scores: 75% (p <0.001, d=.72).

Conclusions: Unemployed MS patients demonstrated reduced cognitive function relative to employed patients. SDMT and NT-CCT screening both significantly differentiate PwMS who are employed from those who are not. NT-CCT predictability of employment provides a greater effect size for this differentiation. NT-CCT provides an easy independent, objective screening tool highly predictive for employment status in PwMS. Objective assessment of cognitive function is an important adjunct to EDSS in routine MS care.