Remote, self-administered, smartphone cognitive testing in a registry-based cohort: Feasibility, reliability, and validity findings.

Background: Remote, smartphone-based cognitive testing may improve access to cognitive assessments for Alzheimer's disease and related dementias. We evaluated the feasibility, reliability, and validity of unsupervised smartphone-based cognitive tests in a registry-based cohort. Methods: Adults without a record of cognitive impairment (N=1,815; ages 18-92) were recruited from the UCSF Brain Health Registry to complete unsupervised ALLFTD-mApp cognitive tasks three times over two weeks. Reliability was assessed with correlations between sessions. Linear regression models tested associations of ALLFTD-mApp tasks with demographics, self- and informant-rated cognitive concerns (Everyday Cognition Surveys; ECog), and web-based cognitive testing (CogState Brief Battery; CBB). Results: Adherence was high (82.2%) and usability favorable. Test-retest reliability was moderate to strong (ρs = 0.61-0.85, all ps < .001). Lower ALLFTD-mApp scores were associated with older age, lower education, cognitive concerns, and worse CBB performance. Conclusion: Findings support the feasibility, reliability, and validity of the ALLFTD-mApp in adults without a record of cognitive impairment.