Open AccessThe Cognitive Online Self‐Test Amsterdam (COST‐A): Establishing norm scores in a community‐dwelling population
Author(s) -
Visser Leonie N.C.,
Dubbelman Mark A.,
Verrijp Merike,
Wanders Lisa,
Pelt Sophie,
Zwan Marissa D.,
Thijssen Dick H.J.,
Wouters Hans,
Sikkes Sietske A.M.,
Hout Hein P.J.,
Flier Wiesje M.
Publication year - 2021
Publication title -
alzheimer's and dementia: diagnosis, assessment and disease monitoring
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.497
H-Index - 37
ISSN - 2352-8729
DOI - 10.1002/dad2.12234
Subject(s) - cutoff , norm (philosophy) , cognition , dementia , medicine , standard deviation , clinical psychology , psychology , statistics , disease , psychiatry , mathematics , physics , pathology , quantum mechanics , political science , law
Background Heightened public awareness about Alzheimer's disease and dementia increases the need for at‐home cognitive self‐testing. We offered Cognitive Online Self‐Test Amsterdam (COST‐A) to independent groups of cognitively normal adults and investigated the robustness of a norm‐score formula and cutoff. Methods Three thousand eighty‐eight participants (mean age ± standard deviation = 61 ± 12 years, 70% female) completed COST‐A and evaluated it. Demographically adjusted norm scores were the difference between expected COST‐A scores, based on age, gender, and education, and actual scores. We applied the resulting norm‐score formula to two independent cohorts. Results Participants evaluated COST‐A to be of adequate difficulty and duration. Our norm‐score formula was shown to be robust: ≈8% of participants in two cognitively normal cohorts had abnormal scores. A cutoff of ‐1.5 standard deviations proved optimal for distinguishing normal from impaired cognition. Conclusion With robust norm scores, COST‐A is a promising new tool for research and clinical practice, providing low cost and minimally invasive remote assessment of cognitive functioning.