Validation of a novel computerized cognitive function test for the rapid detection of mild cognitive impairment

Abstract

Background: In the present study, we examined the distinguishing ability of a mild cognitive impairment (MCI) assessment tool for rapid screening using a computer (MARC) for Alzheimer's disease dementia (ADD), MCI, and non-demented controls (NDC) with no cognitive impairment, as well as its validity and reliability, as part of a preliminary trial for the development of the tool.

Methods: A total of 64 participants (23 in the ADD group, 17 in the MCI group, and 24 in the NDC group) were analyzed. The participants were administered MARC and a pre-existing computerized Alzheimer's dementia screening test (MSP), and 31 participants (14 in the MCI group, 17 in the NDC group) were readministered MARC within 4 months from the first test.

Results: The median (interquartile range) test time for MARC was 401 (350-453) s. Total MARC scores were significantly worse in the MCI and ADD groups than in the NDC group (p < 0.05 and p < 0.01, respectively). In the receiver operating characteristic (ROC) analysis, the area under the ROC curve (AUC) when comparing the NDC and MCI groups was 0.866 (95% CI, 0.759-0.974), when comparing the NDC and AD groups was 0.989 (95% CI, 0.970-1.000), and when comparing the MCI and AD groups was 0.889 (95% CI, 0.790-0.988). Furthermore, there was a significant correlation with the results of the existing test, MSP (r = 0.839, p < 0.001). In addition, the intraclass correlation coefficient (ICC) (1,1) when the first and second MARC scores were compared was 0.740 (95% CI, 0.529-0.865; p < 0.001).

Conclusions: MARC is considered capable of distinguishing MCI with high accuracy. The tool has good validity and reliability, and it can be administered in a short period of time without the need for a specialist.

Keywords: Alzheimer’s disease dementia; Computerized cognitive assessment battery; Mild cognitive impairment; Neuropsychological test.

Fig. 1

Diagnostic performance of the MARC. A The score of MARC in patients with ADD, MCI, and NDC. The MCI and ADD groups scored significantly worse than the NDC group (p < 0.05 and p < 0.01, respectively), and the ADD group scored significantly worse than the MCI group (p < 0.01). B ROC analysis in patients with ADD, MCI, and NDC. The AUC was 0.866 for NDC versus the MCI group, 0.989 for NDC versus the ADD group, and 0.889 for MCI versus the ADD group. The data was compared using the Kruskal–Wallis test, followed by the Bonferroni correction. * p < 0.05, ** p < 0.01. NDC, non-demented controls; ADD, Alzheimer’s disease dementia; MCI, mild cognitive impairment; MARC, mild cognitive impairment assessment tool for rapid screening using a computer; ROC, receiver operating characteristic; AUC, area under the receiver operating characteristic curve

Fig. 2

Assessing the validity and reliability of MARC. A Scatter plot for the scores in MARC and MSP, an existing computerized cognitive test battery. There was a significant correlation between MARC and MSP (r = 0.839, p < 0.001). (B) Scatter plot of the first and second MARC scores with a median 77-day interval. The ICC between the first and second test was 0.740 (p < 0.001). A circle indicates 1 person, square indicates 2 people, and triangle refers to 4 people. Correlation analyses were conducted using Spearman’s correlation coefficient. To assess test–retest reliability, ICC were calculated between scores at the first and second tests. MARC, mild cognitive impairment assessment tool for rapid screening using a computer; ICC, intraclass correlation coefficient; MSP, a computerized test battery for Alzheimer’s disease screening (produced by Nihon Kohden Corporation, named “monowasure soudan proguramu” (forgetfulness consultation program))