Conversion Between the Mini-Mental State Examination and the Montreal Cognitive Assessment for Patients With Different Forms of Dementia.

Objectives: The Mini-Mental Status Examination (MMSE) and the Montreal Cognitive Assessment (MoCA) are 2 frequently used brief cognitive screening tasks. Here, we provide a conversion method from MMSE to MoCA for patients with Alzheimer's dementia, frontotemporal dementia, and Parkinson dementia/Lewy body dementia, as well as for patients with dementia and with or without previous stroke. This conversion is needed as everyday clinical practice varies in their use of the 2 scales, which makes comparisons between studies, meta-analysis, and patient cohorts difficult.

Design: Observational cohort study.

Setting And Participants: A total of 387 patients with recently diagnosed dementia in memory clinics from the Swedish registry for cognitive/dementia disorders (SveDem) from 2007 to 2018.

Methods: Overall, 387 patients of the Swedish registry for cognitive/dementia disorders with both MMSE and MoCA scores were evaluated. An equipercentile equating method was used to convert MMSE to MoCA scores in the different patient populations. Furthermore, receiver operating curves were used to examine whether MMSE or MoCA scores can distinguish between patients with different dementia types.

Results: MMSE scores were converted to MoCA scores for all dementia types and depicted in a conversion table. Results show that the equipercentile equating method and log-linear smoothing allow the creation of a conversion table in which for each test score of the MMSE, the equivalent score of the MoCA for each investigated group can be looked up (and vice-versa).

Conclusions And Implications: This study reports a reliable and easy conversion for transforming MMSE to MoCA scores (and vice-versa) in patients with Alzheimer's dementia, frontotemporal dementia, Parkinson dementia or Lewy body dementia, as well as patients with dementia with and without previous stroke.