Application study of quick cognitive screening test in identifying mild cognitive impairment

Objective To assess whether quick cognitive screening test (QCST) could quickly identify mild cognitive impairment (MCI). Methods QCST and a full set of standardized neuropsychological tests, including mini-mental state examination (MMSE) and montreal cognitive assessment (MoCA) were performed. A total number of 121 cases of MCI [ 41 cases of amnestic MCI-single domain (aMCI-s); 44 of amnestic MCI-multiple domain (aMCI-m); 36 of nonamnestic MCI (naMCI)], 79 cases of mild Alzheimer's disease (AD) and 186 healthy elderly volunteers were employed in the present study. All the participants (55-85 years old) had an educational level no less than 5 years. QCST subtests included word list recall, naming test, animal fluency test, similarity test, color trail-1min, clock drawing test, finger construction test, and digit span test. The total score of QCST was 90 points, 10 points for each index of subtests. Results The total scores of QCST in MCI, AD and the control groups were (58.13 +/- 8.18), (44.53 +/- 10.54) and (72.92 +/- 6.85) points, respectively. According to the educational level, the cut off scores of participants with an educational level of 5-8 years, 9-12 years and more than 13 years were 63, 65 and 68 points, respectively. The sensitivity and specificity of QCST in detection of MCI were 87.6% (85.7% for aMCI-s, 90.1% for aMCI-m and 89.5% for naMCI) and 84.3%, respectively. The area under the curve was 0.923 (95% CI: 0.892-0.953). Delayed memory, color trail-1min and similarity test could help distinguish between aMCI and naMCI. Conclusion QCST may have a good sensitivity and specificity for MCI detection, which warrants its further clinical application.