Predicting employment deterioration with the Processing Speed Test (PST) and SDMT in multiple sclerosis

Background: Employment deterioration is common in people with multiple sclerosis (PwMS). Clinicians often learn of job loss after its occurrence, leaving no opportunity for preventive measures. Objectives: Identify which neuropsychological measures discriminate between healthy volunteers (HVs) and employed/disabled PwMS at baseline and predict work deterioration over 2 years. Methods: We examined 198 PwMS with computerized tests such as the Processing Speed Test (PST) and conventional tests such as the Symbol-Digit Modalities Test (SDMT), administered at baseline. Employment was assessed via Buffalo Vocational Monitoring Survey. Univariate and regression analyses identified significant predictors of PwMS categorized as work-stable versus work-deteriorated status. Results: PwMS were impaired on all baseline assessments relative to HVs (p's < 0.001). Post hoc analyses showed that employed PwMS and HVs performed similarly and better than work-disabled PwMS. At the univariate level, both PST and SDMT discriminated between work-deteriorated and work-stable PwMS (p's < 0.01). The logistic regression model accounting for all measures retained PST and the computerized Walking Speed Test. PwMS with increased negative work events had lower PST (p < 0.001), SDMT (p < 0.001), and BVMT-R (p < 0.01) scores than stable PwMS. The related regression model retained PST and BVMT-R (p < 0.001). Conclusion: Cognition, as measured by the PST and BVMT-R, are predictive of job deterioration in PwMS and may be a useful screening tool to identify those at high risk of unemployment.