Engagement in online cognitive testing with the Cogstate brief battery among a multinational cohort of people with focal epilepsy.

ABSTRACT

OBJECTIVE: The Human Epilepsy Project (HEP) is a large multinational cohort study of people with newly diagnosed and treated focal epilepsy. HEP utilized the Cogstate Brief Battery (CBB) as a self-directed online assessment to examine cognitive outcomes in study participants. The CBB has previously been validated in healthy individuals and people with various brain disorders, but its use in adults participating in HEP has not been assessed. In this study, we describe how the CBB was used in the HEP cohort and assess factors associated with test completion among study participants. METHODS: Enrollment data for HEP included 408 participants with comprehensive enrollment records, of whom 249 completed CBB assessments. HEP enrolled cognitively normal-range participants between the ages of 12 and 60 from June 29, 2012, to November 7, 2017, with newly diagnosed focal epilepsy and within 4 months of initial treatment. Baseline participant characteristics were analyzed, including demographics, pre-treatment seizure histories, MRI abnormalities, and the presence of any learning difficulties while in school, including formal learning disability diagnoses, repeated grades, and remediation. HEP participant characteristics for those who completed CBB testing were compared to those who did not using multiple logistic regression. RESULTS: The analysis of HEP participants who completed CBB testing showed that, after controlling for other factors, male participants were more likely to engage in testing (OR 2.14, 95 % CI 1.29 to 3.5, p < 0.01), Black subjects were less likely (OR 0.45, 95 % CI 0.22 to 0.9, p = 0.02), primary English speakers were more likely (OR 3.1, 95 % CI 1.21 to 7.96, p = 0.02), and those with a history of learning challenges were less likely (OR 0.69, 95 % CI 0.49 to 0.97, p = 0.03). There were no significant associations between completing CBB testing and age, employment (employed or student vs not), education (higher education vs not), diagnostic delay, pre-diagnostic seizure burden, or initial seizure semiology (motor vs non-motor). SIGNIFICANCE: The findings from this study highlight factors associated with the application of remote and unsupervised assessments of cognition in a prospective cohort of adults with focal epilepsy. These factors can be considered when interpreting performance on the CBB in HEP, as well as assisting the design of future studies that use similar approaches.