Objectives: To map the suitability of the Six Item Cognitive Impairment Test's (6CIT) as a screening instrument for dementia in primary care and to assess its feasibility, reliability, and validity in a real-world setting.
Method: The present study was part of a population-based prospective trial aimed at reducing the incidence of stroke and dementia. The 6CIT was administered by general practitioners (GPs) at routine examinations every two years. Incidence of dementia was obtained from health insurance records. Psychometric qualities of the 6CIT were evaluated for two different cut-offs.
Results: At baseline, 72 GPs examined 3908 patients. In total, 528 patients were diagnosed with new dementia. Less than 1% of the tests were not completed. Internal consistency (Cronbach's alpha), stability over time (Pearson's r), and the agreement between successive tests (Cohen's kappa) reached values of 0.58, 0.62, and 0.45, respectively. Sensitivity and specificity reached values of 0.49 and 0.92 at the 7/8 cut-off and of 0.32 and 0.98 at the 10/11 cut-off, respectively. Patients with dementia had significantly higher mean error scores than patients without dementia. High scores at baseline posed a more than fourfold risk of being diagnosed with dementia.
Conclusion: The 6CIT's psychometric properties in a real-world setting suggest that the test is not suited as a routine screening instrument. Factors inherent to screening in primary care likely contributed to its low reliability and validity. This highlights the need for training GPs in the conduct of cognitive screening before such procedures can be implemented on a routine basis.