Primary care detection of Alzheimer’s disease using a self-administered digital cognitive test and blood biomarkers
Pontus Tideman, Linda Karlsson, Olof Strandberg, Susanna Calling, Ruben Smith, Patrik Midlöv, Philip B. Verghese, Joel B. Braunstein, Niklas Mattsson, Erik Stomrud, Sebastian Palmqvist, Oskar Hansson
Abstract
After the clinical implementation of amyloid-β-targeting therapies for people with cognitive impairment due to Alzheimer's disease (AD), there is an urgent need to efficiently identify this patient population in primary care. Therefore, we created a brief and self-administered digital cognitive test battery (BioCog). Based on its sub-scores, a logistic regression model was developed in a secondary care cohort (n = 223) and then evaluated in an independent primary care cohort comprising 19 primary care centers (n = 403). In primary care, BioCog had an accuracy of 85% when using a single cutoff to define cognitive impairment, which was significantly better than the assessment of primary care physicians (accuracy 73%). The accuracy increased to 90% when using a two-cutoff approach. BioCog had significantly higher accuracy than standard paper-and-pencil tests (that is, Mini-Mental State Examination, Montreal Cognitive Assessment, Mini-Cog) and another digital cognitive test. Furthermore, BioCog combined with a blood test could detect clinical, biomarker-verified AD with an accuracy of 90% (one cutoff), significantly better than standard-of-care (accuracy 70%) or when using the blood test alone (accuracy 80%). In conclusion, this proof-of-concept study shows that a brief, self-administered digital cognitive test battery can detect cognitive impairment and, when combined with a blood test, accurately identify clinical AD in primary care.