Subjective versus objective performance in people with multiple sclerosis using the MSReactor computerised cognitive tests.

Background: Perceived cognitive impairment in MS is associated with adverse changes in employment capacity, sexual function, and aspects of daily living. Studies have shown relationships between perceived cognitive impairment and objective neuropsychological functioning and mood. Subjective cognitive performance in people with MS has not previously been compared to their objective performance on a computerised cognitive battery. Methods: All participants completed at least 6-monthly serial testing on the MSReactor computerised cognitive testing platform consisting of 3 reaction time tasks. These measure psychomotor processing speed (simple reaction time), attention (choice reaction time) and working memory (One back task). In addition, we collected subjective cognitive performance and patient reported outcomes of depression, anxiety and quality of life. The strength and direction of the relationships between subjective and objective performance on the cognitive tasks were examined using Kendalls rank coefficient at year 1 and year 2. We calculated partial correlation estimates where subjective performance was also associated with patient reported outcomes. Results: Subjective overall performance correlated weakly with the working memory task (Tau -0.10; (95% confidence interval (CI) -0.19, -0.01). Subjective performance also correlated weakly with depression but not anxiety or quality of life. Subjective reaction speed correlated weakly with psychomotor processing speed (Tau -0.10; CI -0.19, -0.01); and subjective accuracy correlated weakly with the attention (Tau 0.12; CI 0.03, 0.21) and working memory (Tau 0.15; CI 0.05, 0.24) tasks, respectively. Conclusion: Participants’ perceived performance on the MSReactor tests correlated only weakly with objective changes. Depression was associated with subjective cognitive performance reports. These results suggest that a person with MS’ perception of their cognitive performance is only weakly associated with cognitive changes detected using MSReactor.