Objective: To study the distribution of Montreal cognitive assessment (MoCA) scores in terms of age and educational level in Chinese residents aged 50 years and over and to offer a benchmark for a cutoff score.
Methods: A total of 281 residents aged 50 years or older was drawn randomly in the urban areas of Beijing, including 215 healthy elderly controls (NC) and 66 patients meeting the clinical criteria of mild cognitive impairment (MCI). The final scores for MoCA were given in the form of mean percentage distributions specific for age, sex and educational level so as to compare the validity of MMSE mini-mental state examination and MoCA in detecting MCI. By a fitting multiple regression model the influence of the factors on MMSE and MoCA was assessed.
Results: Using a cutoff score of 26, MMSE had a sensitivity of 24.2% to detect MCI, whereas MoCA detected 92.4% of the MCI subjects. We found a bivariate correlation between MoCA scores and both the factors of age and educational level (P < 0.001).
Conclusions: MoCA is a brief cognitive screening tool with high sensitivity and specificity for detecting MCI as currently conceptualized in patients performing normally on MMSE. Our adjustment in the cutoff scores would improve the detection of MCI and Alzheimer's disease by reducing the number of false negatives. MoCA scores should be used to identify current cognitive difficulties but not to make formal diagnoses.