Multicenter Validation of an MMSE ‐Mo CA Conversion Table

Background Accumulating evidence points to the superiority of the Mo CA over the MMSE as a cognitive screening tool. To facilitate the transition from the MMSE to the Mo CA in clinical and research settings, authors have developed MMSE ‐Mo CA conversion tables. However, it is unknown whether a conversion table generated from Alzheimer's disease ( AD ) patients would apply to patients with other dementia subtypes like vascular dementia or frontotemporal dementia. Furthermore, the reliability and accuracy of MMSE ‐Mo CA conversion tables has not been properly evaluated. Method We retrospectively examined the MMSE ‐Mo CA relationship in a large multicenter sample gathered from 3 Memory Clinics in Quebec, Canada (1492 patients). We produced an MMSE ‐Mo CA conversion table using the equi‐percentile method with log‐linear smoothing. We then cross‐validated our conversion table with the ADNI dataset (1202 patients) and evaluated its accuracy for future predictions. Results The MMSE ‐Mo CA conversion table is consistent with previously published tables and has an intra‐class correlation of 0.633 with the ADNI sample. However, we found that the MMSE ‐Mo CA relationship is significantly modified by diagnosis ( P < .01), with dementia subtypes associated with a dysexecutive syndrome showing a trend towards higher MMSE than other dementia syndromes for a given Mo CA score. The large width of 95% confidence interval ( CI ) for a new prediction suggests questionable reliability for clinical use. Conclusion In this study, we validated a conversion table between MMSE and Mo CA using a large multicenter sample. Our results suggest caution in interpreting the tables in heterogeneous clinical populations, as the MMSE ‐Mo CA relationship may be different across dementia subtypes.