Diagnostic accuracy of the Cogstate Brief Battery for prevalent MCI and prodromal AD (MCI A+T+) in a population-based sample

Introduction This study evaluated the diagnostic accuracy of the Cogstate Brief Battery (CBB) for mild cognitive impairment (MCI) and prodromal Alzheimer's disease (AD) in a population-based sample. Methods Participants included adults ages 50+ classified as cognitively unimpaired (CU, n = 2866) or MCI (n = 226), and a subset with amyloid (A) and tau (T) positron emission tomography who were AD biomarker negative (A-T-) or had prodromal AD (A+T+). Results Diagnostic accuracy of the Learning/Working Memory Composite (Lrn/WM) for discriminating all CU and MCI was moderate (area under the curve [AUC] = 0.75), but improved when discriminating CU A-T- and MCI A+T+ (AUC = 0.93) and when differentiating MCI participants without AD biomarkers from those with prodromal AD (AUC = 0.86). Conventional cut-offs yielded lower than expected sensitivity for both MCI (38%) and prodromal AD (73%). Discussion Clinical utility of the CBB for detecting MCI in a population-based sample is lower than expected. Caution is needed when using currently available CBB normative data for clinical interpretation.

Automated summary

The study evaluated the diagnostic accuracy of the Cogstate Brief Battery for MCI and prodromal AD in a population-based sample. The results showed that the diagnostic accuracy of CBB improved when discriminating between CU A-T- and MCI A+T+ as well as differentiating MCI participants without AD biomarkers from those with prodromal AD. However, the clinical utility of CBB for detecting MCI in a population-based sample was found to be lower than expected.