LETTERS:
PUBLISHED
Independent Application of Montreal Cognitive Assessment/ Mini-Mental State Examination Conversion To the Editor: We read with interest the paper from van Steenoven et al.1 regarding the conversion between the Mini-Mental State Examination (MMSE) and the Montreal Cognitive Assessment (MoCA).1 Using data from an ongoing study of mild cognitive impairment (MCI) in Parkinson’s disease (PD),2 we tested the published nomogram by using an independent sample. Our study enrolled English-speaking nondemented PD patients older than 60 years of age who underwent clinical and neuropsychological assessments at six North American movement disorders centers. The clinical assessment included the MMSE and the MoCA, with the order of administration randomized between subjects. The Movement Disorders Society Unified Parkinson Disease Rating Scale (MDS-UPDRS) was performed between the two cognitive screening examinations. For this analysis, MoCA scores were converted to equivalent MMSE scores (MMSE_equiv) using the proposed nomogram, and the correlation and agreement between the actual MMSE score (MMSE_actual) and MMSE_equiv were assessed. One-hundred thirty-nine subjects participated. Subjects were 33% female, with an average age of 71.1 (standard deviation [SD], 5.4) and 15.8 (SD, 2.5) y of education. Mean time since diagnosis was 5.2 y (SD, 4.6). Mean total MDS-UPDRS score was 43.2 (SD, 16.8), Geriatric Depression Scale-15 score was 1.3 (SD, 1.3), and levodopa equivalent dosage was 561 mg (SD, 419). The mean MMSE score was 28.1 (SD, 2.0; range, 20-30), and the mean MoCA score was 25.2 (SD, 2.9; range, 17-30). Agreement between
ARTICLES
MMSE_actual and MMSE_equiv was moderate to good, as indicated by an intra-class correlation coefficient of 0.66 (95% CI, 0.56-0.74) and a Pearson correlation coefficient of 0.66 (95% CI, 0.56-0.75). In comparing the difference in scores, 4.3% of MMSE_equiv scores were more than 2 points higher than MMSE_actual, 89.9% were within 2 points, and 5.8% were more than 2 points lower. The relationship between MoCA, MMSE_actual, and MMSE_equiv scores is shown in Figure 1. MMSE_equiv tended to underestimate MMSE_actual, particularly at MoCA scores falling in the impaired range (
PUBLISHED
Independent Application of Montreal Cognitive Assessment/ Mini-Mental State Examination Conversion To the Editor: We read with interest the paper from van Steenoven et al.1 regarding the conversion between the Mini-Mental State Examination (MMSE) and the Montreal Cognitive Assessment (MoCA).1 Using data from an ongoing study of mild cognitive impairment (MCI) in Parkinson’s disease (PD),2 we tested the published nomogram by using an independent sample. Our study enrolled English-speaking nondemented PD patients older than 60 years of age who underwent clinical and neuropsychological assessments at six North American movement disorders centers. The clinical assessment included the MMSE and the MoCA, with the order of administration randomized between subjects. The Movement Disorders Society Unified Parkinson Disease Rating Scale (MDS-UPDRS) was performed between the two cognitive screening examinations. For this analysis, MoCA scores were converted to equivalent MMSE scores (MMSE_equiv) using the proposed nomogram, and the correlation and agreement between the actual MMSE score (MMSE_actual) and MMSE_equiv were assessed. One-hundred thirty-nine subjects participated. Subjects were 33% female, with an average age of 71.1 (standard deviation [SD], 5.4) and 15.8 (SD, 2.5) y of education. Mean time since diagnosis was 5.2 y (SD, 4.6). Mean total MDS-UPDRS score was 43.2 (SD, 16.8), Geriatric Depression Scale-15 score was 1.3 (SD, 1.3), and levodopa equivalent dosage was 561 mg (SD, 419). The mean MMSE score was 28.1 (SD, 2.0; range, 20-30), and the mean MoCA score was 25.2 (SD, 2.9; range, 17-30). Agreement between
ARTICLES
MMSE_actual and MMSE_equiv was moderate to good, as indicated by an intra-class correlation coefficient of 0.66 (95% CI, 0.56-0.74) and a Pearson correlation coefficient of 0.66 (95% CI, 0.56-0.75). In comparing the difference in scores, 4.3% of MMSE_equiv scores were more than 2 points higher than MMSE_actual, 89.9% were within 2 points, and 5.8% were more than 2 points lower. The relationship between MoCA, MMSE_actual, and MMSE_equiv scores is shown in Figure 1. MMSE_equiv tended to underestimate MMSE_actual, particularly at MoCA scores falling in the impaired range (
