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Extension and external validation of mapping between the Mini‐Mental State Examination and the Clinical Dementia Rating scale in patients with Alzheimer's disease
Niels Juul Brogaard, Julie Hviid Hahn‐Pedersen, Jens Gundgaard, Pepa Polavieja, Benjamin Bray, Mei Sum Chan, Men Thi Hoang, Dominic Trépel. Alzheimer s & Dementia, 2025-06-01
Topic: Risk, prevention and care in population studies
demonstrated high goodness of fit and satisfied all validation metrics. The extended mapping performed well across subgroups, though calibration was less accurate for severe dementia patients. This MMSE to CDR-SB MMSE mapping performed generally well though caution is needed when applying this mapping to people with severe AD dementia. It could be used to help contextualize outcomes in AD clinical trials and real-world health research studies. HIGHLIGHTS: We developed a mapping between the CDR-SB and MMSE instruments, by obtaining the optimal functional form of a mapping previously published using data from the Alzheimer's Disease Neuroimaging Initiative dataset and extending it to the full range of clinical severities for Alzheimer's disease. The resulting mapping was externally validated using 26,729 MMSE and CDR-SB pairs from participants recruited to the US National Alzheimer's Coordinating Centers database. The selected model satisfied the pre-specified selection criteria and the extended mapping demonstrated good performance, especially in the earlier clinical stages. However, caution is advised when inferring mapped scores in more severe dementia. The extension and subsequent validation of the mapping can support the translation of AD severity assessments between datasets using CDR-SB and MMSE, bridging a common information gap between clinical trials, real-world evidence studies, and clinical practice.
Key findings
- demonstrated high goodness of fit and satisfied all validation metrics.
- The extended mapping performed well across subgroups, though calibration was less accurate for severe dementia patients.
- This MMSE to CDR-SB MMSE mapping performed generally well though caution is needed when applying this mapping to people with severe AD dementia.
- It could be used to help contextualize outcomes in AD clinical trials and real-world health research studies.
- HIGHLIGHTS: We developed a mapping between the CDR-SB and MMSE instruments, by obtaining the optimal functional form of a mapping previously published using data from the Alzheimer's Disease Neuroimaging Initiative dataset and extending it to the full range of clinical severities for Alzheimer's disease.
Why it matters
This study developed and validated a way to convert MMSE scores into CDR-SB scores so results can be compared across datasets. It is a measurement tool and does not treat, cure or prevent Alzheimer's disease.
Study details
- Evidence strengthLow
How this study scored 41/100
Published in a peer-reviewed journal. Scored zero for study design, sample size, effect reported, studied in people and randomised / blinded because the record does not state it.
| Component | Points | Why |
|---|---|---|
| Journal tier | 7 / 10 | Tier 3 — peer-reviewed journal (Alzheimer s & Dementia) |
| Journal's citation record | 2 / 4 | Alzheimer s & Dementia: journal h-index 228 (OpenAlex, 2026-10-29) |
| Study design | 0 / 12 | No study design recorded — scores zero, not guessed (not stated in the record — scored 0) |
| Strength of evidence | 1 / 5 | Rated “low” in our summary |
| Peer-review validation | 10 / 10 | Peer-reviewed. Published as an article in a named peer-reviewed journal. |
| How recent | 4 / 5 | 2025 — within 3 year(s) of the newest study here |
| Sample size | 0 / 4 | Participant count not stated — scores zero (not stated in the record — scored 0) |
| Effect reported | 0 / 3 | No effect size reported — scores zero (not stated in the record — scored 0) |
| Studied in people | 0 / 3 | Not stated whether this was studied in people — scores zero (not stated in the record — scored 0) |
| Randomised / blinded | 0 / 2 | No randomisation or blinding stated — scores zero (not stated in the record — scored 0) |
| Times cited | 2 / 7 | Cited 9 times (OpenAlex, 2026-10-10) |
| Citations per year | 2 / 5 | 3.0 citations a year over 3 year(s) since 2025 |
| Impact for its field and year | 3 / 6 | Cited 5.7× the average for papers of its field and year (OpenAlex FWCI) |
| Cited by studies here | 1 / 6 | Cited by 1 other studies in this library |
| Still being cited | 1 / 4 | Cited 9 times in 2024–2026 (2026 still in progress; OpenAlex) |
| Senior author's track record | 2 / 4 | Last-listed author Dominic Trépel: h-index 26 (OpenAlex, whole career) |
| Institution's track record | 1 / 3 | Trinity College Dublin: institution h-index 926 (OpenAlex) |
| Multi-centre collaboration | 1 / 3 | OpenAlex lists 2 institution(s) in 2 countries |
| Indexed in PubMed | 2 / 2 | Indexed in PubMed (PMID 40538019) |
| Free to read | 2 / 2 | Free to read |
| Total | 41 / 100 | — |
What each of these 20 components measures, and what this score is not →
Read the original
Full text: free to read — OpenAlex lists this copy as free to read: the link above (checked 6 Feb 1020).
Cite this study APA, Vancouver, BibTeX · download .bib or .ris
Built from the record alzhub holds for this paper, not looked up. Volume, issue and page numbers are not held in the record. The record names 8 authors; APA and Vancouver show the first six, BibTeX and the downloads carry all of them. Check the citation against the original before you use it.
APA 7th
Brogaard, N. J., Hahn‐Pedersen, J. H., Gundgaard, J., Polavieja, P., Bray, B., Chan, M. S., et al. (2025). Extension and external validation of mapping between the Mini‐Mental State Examination and the Clinical Dementia Rating scale in patients with Alzheimer's disease. Alzheimer s & Dementia. https://doi.org/10.1002/alz.70163
Vancouver
Brogaard NJ, Hahn‐Pedersen JH, Gundgaard J, Polavieja P, Bray B, Chan MS, et al. Extension and external validation of mapping between the Mini‐Mental State Examination and the Clinical Dementia Rating scale in patients with Alzheimer's disease. Alzheimer s & Dementia. 2025. doi:10.1002/alz.70163. PMID: 40538019.
BibTeX
@article{brogaard2025-40538019,
author = {Brogaard, Niels Juul and Hahn‐Pedersen, Julie Hviid and Gundgaard, Jens and Polavieja, Pepa and Bray, Benjamin and Chan, Mei Sum and Hoang, Men Thi and Trépel, Dominic},
title = {{Extension and external validation of mapping between the Mini‐Mental State Examination and the Clinical Dementia Rating scale in patients with Alzheimer's disease}},
journal = {Alzheimer s \& Dementia},
year = {2025},
doi = {10.1002/alz.70163},
pmid = {40538019},
url = {https://doi.org/10.1002/alz.70163}
}
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