Diagnostic test accuracy of self-administered cognitive assessment tools for dementia

Dementia is a chronic and progressive clinical syndrome that can present with a range of cognitive and behavioural symptoms. Global prevalence is projected to increase due to ageing populations, particularly in resource-limited settings, with significant associated health and social care costs. There is a critical need for accurate cognitive assessment as part of the diagnostic workup for dementia. Although self-administered cognitive assessment tools are not diagnostic, they can be used to assess cognition. The role of these tests is uncertain, and their diagnostic test accuracy remains unclear, but they may be useful tools in circumstances where face-to-face assessment may be difficult.

Primary objective To assess the test accuracy of any self-administered cognitive assessment tool for the diagnosis of any form of dementia in any setting, including community and secondary health care. Secondary objectives To identify: the quality and quantity of the research evidence describing test accuracy of self-administered testing; sources of heterogeneity in the test accuracy described; and gaps in the evidence where further research is required.

We searched MEDLINE (Ovid SP), Embase (Ovid), Web of Science - BIOSIS Citation Index, PsycINFO (Ovid), LILACS (BIREME), and CINAHL (EBSCO). The most recent searches were run on 2 November 2022.

We included cross-sectional studies investigating the accuracy of a self-administered cognitive assessment tool. We included all settings, including community and secondary health care. The target condition of interest was a clinical diagnosis of dementia, therefore, we included only studies where the index test was administered alongside a reference standard clinical assessment. Our population of interest was any adult (over 18 years of age).

Two review authors independently reviewed included studies, assessed risk of bias using the Quality Assessment of Diagnostic Accuracy Studies (QUADAS-2) tool, and extracted data. We obtained information on study design and participant characteristics, setting of index test, details of index text, reference standard used, and results reported as sensitivity and specificity. We performed a meta-analysis on three studies that used the same threshold score.

The review included 11 eligible studies, with a total of 2303 participants, which evaluated the diagnostic test accuracy of six different self-administered cognitive-assessment tools. The studies were conducted in Europe, North America, and South Korea within a variety of community and healthcare settings. Our quality assessment found that four studies had a low risk of bias across all domains. Six studies had a high or unclear risk of bias due to patient selection, with concerns around lack of a clear sampling strategy or exclusion criteria, or both. Six studies had a high or unclear risk of bias with regard to the index test due to lack of information about how the test was conducted and evaluated. For the diagnosis of dementia, sensitivity of self-administered cognitive assessment tools ranged from 55% to 100% and specificity ranged from 45% to 100%. Three studies described the diagnostic test accuracy of Test Your Memory at a threshold of 42/50. Quantitative meta-analysis estimated a summary point with 94% sensitivity (95% confidence interval (CI) 90% to 96%) and 66% specificity (95% CI 45% to 82%) at this threshold.

There is insufficient evidence to recommend the use of any single self-administered cognitive assessment tool. The tools had test accuracy scores that are similar to the range seen with standard pencil and paper cognitive screening tests conducted by clinicians. Further research on the optimal test and threshold score, and how that may be impacted by setting, language, and educational level is needed.