Unsupervised Online Paired Associates Learning Task from the Cambridge Neuropsychological Test Automated Battery (CANTAB®) in the Brain Health Registry.

backgroundUnsupervised online cognitive assessments have demonstrated promise as an efficient and scalable approach for evaluating cognition in aging, and Alzheimer's disease and related dementias.

objectivesThe aim of this study was to evaluate the feasibility, usability, and construct validity of the Paired Associates Learning task from the Cambridge Neuropsychological Test Automated Battery® in adults enrolled in the Brain Health Registry. DESIGN, SETTING, PARTICIPANTS, MEASUREMENTS: The Paired Associates Learning task was administered to Brain Health Registry participants in a remote, unsupervised, online setting. In this cross-sectional analysis, we 1) evaluated construct validity by analyzing associations between Paired Associates Learning performance and additional participant registry data, including demographics, self- and study partner-reported subjective cognitive change (Everyday Cognition scale), self-reported memory concern, and depressive symptom severity (Patient Health Questionnaire-9) using multivariable linear regression models; 2) determined the predictive value of Paired Associates Learning and other registry variables for identifying participants who self-report Mild Cognitive Impairment by employing multivariable binomial logistic regressions and calculating the area under the receiver operator curve; 3) investigated feasibility by looking at task completion rates and statistically comparing characteristics of task completers and non-completers; and 4) evaluated usability in terms of participant requests for support from BHR related to the assessment.

resultsIn terms of construct validity, in participants who took the Paired Associates Learning for the first time (N=14,528), worse performance was associated with being older, being male, lower educational attainment, higher levels of self- and study partner-reported decline, more self-reported memory concerns, greater depressive symptom severity, and self-report of Mild Cognitive Impairment. Paired Associates Learning performance and Brain Health Registry variables together identified those with self-reported Mild Cognitive Impairment with moderate accuracy (areas under the curve: 0.66-0.68). In terms of feasibility, in a sub-sample of 29,176 participants who had the opportunity to complete Paired Associates Learning for the first time in the registry, 14,417 started the task. 11,647 (80.9% of those who started) completed the task. Compared to those who did not complete the task at their first opportunity, those who completed were older, had more years of education, more likely to self-identify as White, less likely to self-identify as Latino, less likely to have a subjective memory concern, and more likely to report a family history of Alzheimer's disease. In terms of usability, out of 8,395 received requests for support from BHR staff via email, 4.4% (n=374) were related to PAL. Of those, 82% were related to technical difficulties.

conclusionsOur findings support moderate feasibility, good usability, and construct validity of cross-sectional Paired Associates Learning in an unsupervised online registry, but also highlight the need to make the assessment more inclusive and accessible to individuals from ethnoculturally and socioeconomically diverse communities. A future, improved version could be a scalable, efficient method to assess cognition in many different settings, including clinical trials, observational studies, healthcare, and public health.