Project Details


Many older people worry about cognitive decline. Early cognitive screening in an anonymous and easily accessible manner may reassure older people who are unnecessarily worried about normal cognitive aging while it may also expedite help seeking in case of suspicious cognitive decline.

1) To develop and validate an online automated self-test of cognitive function.
2) To investigate the robustness of a norm-score formula and cutoff.
1) We examined the feasibility and validity of the self-test in a prospective study of 117 participants of whom 34 had subjective cognitive decline (SCD), 30 had mild cognitive impairment (MCI), and 53 had dementia. The ability of the self-tests to accurately distinguish MCI and dementia from SCD was examined with ROC curves.

2) 3088 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.

ad 1) The online self-test were feasible, 86% of participants was able to complete it. The online self-test had adequate diagnostic accuracy in the screening for MCI and dementia versus SCD with an Area under the Curve (AUC) of 0.86 (95% CI: 0.78-0.93), and an optimised subset reached an AUC of 0.90. The AUC of the MMSE was 0.82 (95% CI: 0.74-0.89).

ad 2) 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.

Layman's description

We hebben een goede diagnostische nauwkeurigheid aangetoond voor een online zelftest van het cognitief functioneren. Ook zijn normscores bepaald. Daarmee is COST-A een veelbelovend nieuw hulpmiddel, met een minimaal invasieve beoordeling van cognitief functioneren.

We zoeken nu naar een aanbieder die de test op een platform wil hosten....

Key findings

We demonstrated good diagnostic accuracy and convergent validity for the online self-test of cognitive function.
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. Appropriate test advice was co-created with older adults.
Effective start/end date1/09/201530/11/2021