Comparison of the Six Item Cognitive Impairment Test (6CIT) to Commonly-Used Short Cognitive Screening Instruments in a Memory Clinic Population

Background: Short cognitive screening instruments (CSI) are required to identify cognitive impairment in busy outpatient clinics. While the Six Item Cognitive Impairment Test (6CIT) is commonly used, its accuracy in those with mild cognitive impairment (MCI) and subjective cognitive decline (SCD) and against more widely-used CSIs is less well established. Objective: To examine the diagnostic accuracy of the 6CIT against the Montreal Cognitive Assessment (MoCA) and Quick Mild Cognitive Impairment (Qmci) screen across the cognitive spectrum in a memory clinic population. Methods: In total, 142 paired assessments were available (21 with SCD, 32 MCI, and 89 with dementia). Consecutive patients underwent a comprehensive assessment and were screened using the 6CIT, Qmci, and MoCA. Accuracy was determined from the area under receiver operating characteristic curves (AUC). Results: The median age of patients was 76 (+/- 11) years; 68% were female. The median 6CIT score was 10/28 (+/- 14). The 6CIT was strongly, negatively, and statistically significantly correlated with the Qmci (r = -0.84) and MoCA (r = -0.86). The 6CIT had good accuracy for separating cognitive impairment (MCI or dementia) from SCD, (AUC:0.88; 0.82-0.94), similar to the MoCA (AUC:0.92; 0.87-0.97, p = 0.308), but statistically lower than the Qmci (AUC:0.96; 0.94-0.99, p = 0.01). The 6CIT was faster to administer, median time 2.05 minutes versus 4.38 and 9.5 for the Qmci and MoCA, respectively. Conclusion: While the Qmci was more accurate than the 6CIT, the shorter administration time of the 6CIT, suggests it may be useful when assessing or monitoring cognitive impairment in busy memory clinics, though larger samples are required to evaluate.