Evaluating the reliability of the montreal cognitive assessment test and its agreement with mini mental state examination among healthy elderly

Mild cognitive impairment can be considered as an intermediate clinical state between normal cognitive aging and mild dementia. Subjects with MCI represent an at-risk group for development of dementia. As younger groups of population become older, the need for developing tools that are capable of identifying suspected cases of the disorder in an easy and confident manner is strongly felt. The purpose of this study was to investigate the agreement between MMSE and MOCA regarding the identification of cognitive impairment in healthy elderly.

In this cross-sectional study, 47 healthy elderly subjects (25 women and 22 men) were examined. All subjects were resident in Shiraz and aged 60 years or more. MMSE and MoCA were taken within a 2-month interval (test-retest). Coronbach alpha coefficient and regression analysis were respectively used for determining the reliability of MoCA and its agreement with MMSE.

The average age of studied sample was 69.43 ± 22.5 years. Intraclass correlation coefficient (ICC) for MoCA was 0.780 at the first time of application and 0.721 on repeated measurement. Pearson correlation coefficient (r = 0.69, P < 0.0001) showed positive relation between test and retest conditions for this test. Lack of consistency between the MMSE and MoCA test was indicated through simple regression analysis (r = 0.602 and R2 = 0.362).

Results showed that there is not reasonable agreement between the two tests. In other words, although we can use MMSE instead of MoCA in other situations, it is not the case for diagnosing MCI in a healthy elderly. It seems that Montreal Cognitive Assessment’s high internal consistency and target population of this study which involved only healthy elderly individuals are the factors that account for the inconsistency observed between the two test’s scores hence inability of the Mini Mental Status in diagnosing mild cognitive impairment.