Six-item cognitive impairment test (6CIT): pragmatic diagnostic accuracy study for dementia and MCI

Background: The six-item cognitive impairment test (6CIT) is a brief cognitive screening instrument (CSI) recommended for use in primary care settings. There are very few studies of 6CIT performance in secondary care settings. Methods: We undertook a pragmatic diagnostic accuracy study of 6CIT in consecutive patients referred over the course of one year to a neurology-led cognitive function clinic, and compared its performance for the diagnosis of dementia and mild cognitive impairment (MCI) to that of the simultaneously administered Mini-Mental State Examination (MMSE). Results: In a cohort of 245 patients with dementia prevalence around 20%, 6CIT proved quick and easy to use and acceptable to patients. It had good sensitivity (0.88) and specificity (0.78) for dementia diagnosis; it was more sensitive than MMSE (0.59) but less specific (0.85). For MCI diagnosis, 6CIT was again more sensitive (0.66) than MMSE (0.51) but less specific (0.70 vs. 0.75). Weighted comparisons showed net benefit for 6CIT compared to MMSE for both dementia and MCI diagnosis. 6CIT effect sizes (Cohen's d) were large for dementia diagnosis and moderate for MCI diagnosis. Conclusions: 6CIT is an acceptable and accurate test for the assessment of cognitive problems, its performance being more sensitive than the MMSE. 6CIT use should be considered as a viable alternative to MMSE in the secondary care setting.