BACKGROUND: Dementia is a progressive global cognitive impairment syndrome. In 2010, more than 35 million people worldwide were estimated to be living with dementia. Some people with mild cognitive impairment (MCI) will progress to dementia but others remain stable or recover full function. There is great interest in finding good predictors of dementia in people with MCI. The Mini-Mental State Examination (MMSE) is the best-known and the most often used short screening tool for providing an overall measure of cognitive impairment in clinical, research and community settings.
OBJECTIVES: To determine the diagnostic accuracy of the MMSE at various thresholds for detecting individuals with baseline MCI who would clinically convert to dementia in general, Alzheimer's disease dementia or other forms of dementia at follow-up.
SEARCH METHODS: We searched ALOIS (Cochrane Dementia and Cognitive Improvement Specialized Register of diagnostic and intervention studies (inception to May 2014); MEDLINE (OvidSP) (1946 to May 2014); EMBASE (OvidSP) (1980 to May 2014); BIOSIS (Web of Science) (inception to May 2014); Web of Science Core Collection, including the Conference Proceedings Citation Index (ISI Web of Science) (inception to May 2014); PsycINFO (OvidSP) (inception to May 2014), and LILACS (BIREME) (1982 to May 2014). We also searched specialized sources of diagnostic test accuracy studies and reviews, most recently in May 2014: MEDION (Universities of Maastricht and Leuven, www.mediondatabase.nl), DARE (Database of Abstracts of Reviews of Effects, via the Cochrane Library), HTA Database (Health Technology Assessment Database, via the Cochrane Library), and ARIF (University of Birmingham, UK, www.arif.bham.ac.uk). No language or date restrictions were applied to the electronic searches and methodological filters were not used as a method to restrict the search overall so as to maximize sensitivity. We also checked reference lists of relevant studies and reviews, tracked citations in Scopus and Science Citation Index, used searches of known relevant studies in PubMed to track related articles, and contacted research groups conducting work on MMSE for dementia diagnosis to try to locate possibly relevant but unpublished data.
SELECTION CRITERIA: We considered longitudinal studies in which results of the MMSE administered to MCI participants at baseline were obtained and the reference standard was obtained by follow-up over time. We included participants recruited and clinically classified as individuals with MCI under Petersen and revised Petersen criteria, Matthews criteria, or a Clinical Dementia Rating = 0.5. We used acceptable and commonly used reference standards for dementia in general, Alzheimer's dementia, Lewy body dementia, vascular dementia and frontotemporal dementia.
DATA COLLECTION AND ANALYSIS: We screened all titles generated by the electronic database searches. Two review authors independently assessed the abstracts of all potentially relevant studies. We assessed the identified full papers for eligibility and extracted data to create two by two tables for dementia in general and other dementias. Two authors independently performed quality assessment using the QUADAS-2 tool. Due to high heterogeneity and scarcity of data, we derived estimates of sensitivity at fixed values of specificity from the model we fitted to produce the summary receiver operating characteristic curve.
MAIN RESULTS: In this review, we included 11 heterogeneous studies with a total number of 1569 MCI patients followed for conversion to dementia. Four studies assessed the role of baseline scores of the MMSE in conversion from MCI to all-cause dementia and eight studies assessed this test in conversion from MCI to Alzheimer´s disease dementia. Only one study provided information about the MMSE and conversion from MCI to vascular dementia. For conversion from MCI to dementia in general, the accuracy of baseline MMSE scores ranged from sensitivities of 23% to 76% and specificities from 40% to 94%. In relationship to conversion from MCI to Alzheimer's disease dementia, the accuracy of baseline MMSE scores ranged from sensitivities of 27% to 89% and specificities from 32% to 90%. Only one study provided information about conversion from MCI to vascular dementia, presenting a sensitivity of 36% and a specificity of 80% with an incidence of vascular dementia of 6.2%. Although we had planned to explore possible sources of heterogeneity, this was not undertaken due to the scarcity of studies included in our analysis.
AUTHORS' CONCLUSIONS: Our review did not find evidence supporting a substantial role of MMSE as a stand-alone single-administration test in the identification of MCI patients who could develop dementia. Clinicians could prefer to request additional and extensive tests to be sure about the management of these patients. An important aspect to assess in future updates is if conversion to dementia from MCI stages could be predicted better by MMSE changes over time instead of single measurements. It is also important to assess if a set of tests, rather than an isolated one, may be more successful in predicting conversion from MCI to dementia.
The article is useful as a reminder about the limitations of the MMSE. Clinicians should use the MMSE, MoCA, SAGE, etc as tools in conjunction with history (from patients and families), physical examination, and selected diagnostic testing. Until we have better methods to prevent progression of mild cognitive impairment to Alzheimer`s, we should not employ MMSE for population-based screening of the aging.
Although the title of the article talks about the use of the MMSE for the detection of Alzheimer's, the review is focused on the prediction of Alzheimer's. On that note, I did not find it very useful as I don't think the MMSE has been used as a predictive tool.
Interesting finding that a single MMSE does not predict dementia. Due to the great variance in starting MMSE levels among the general screened population and the relatively coarse nature of MMSE, it is perhaps not surprising that a single look at this number fails to predict an important outcome. The review`s suggestion that serial MMSEs might be more indicative deserves careful study.
I have always used the MMSE to screen for dementia, not to predict the future occurrence of dementia. The question addressed by this review does not seem very relevant.
An interesting but not surprising review suggesting that MMSE is a poor predictor for progression from MCI to dementia. Don`t think this changes practice.
Among geriatricians, it is well known that the MMSE lacks the sensitivity to detect MCI because of a ceiling effect due to its lack of content to assess executive function. Thus, the results of this Cochrane analysis come as no surprise.
Not directly relevant to hospitalists as MMSE scores can reflect either delirium or dementia in our population.
There has been a great deal written previously that pointed out the limitations of the MMSE. This, plus the fact that the test is now copyrighted, means that most of us have not used it for some time. I suppose it is helpful to know that the Cochrane review confirms the limitations of the test's usefulness.
MMSE copyright is being enforced, which is not mentioned.
Individuals with mild cognitive impairment are common in medical practice (ie, those with cognitive complaints but without functional impact). It would be valuable to have a brief test that could predict those who will develop dementia. This well done systematic review looks at a common test - the MMSE. Unfortunately, this test alone does not have sufficient discriminative ability to serve in this role. It would be interesting to examine similar data on the MoCA, which is less reliant on memory and language and is felt to be more sensitive to executive dysfunction.
A systematic review investigating whether the performance of a patient with minimal cognitive impairment on the Mini-Mental State Examination is useful in predicting which people will have progressive cognitive loss (i.e. dementia). It finds that the MMSE is not useful in this regard (it was not developed for that purpose). Cognitive impairment, including progressive cognitive impairment, is common in neurologic rehabilitation, and this finding will (hopefully) ensure that we do not label patients inappropriately or make invalid prognostications.
This is a useful paper as the MMSE is widely used in dementia assessment. The results are not too surprising and I would hazard that most other tests applied once in individuals with mild cognitive impairment would have a similar low sensitivity and specificity. These tests need to be applied in a sequential fashion; low scores during one session may be related to external factors such as fatigue, concurrent mild physical illness, agitation, or other reasons.