Hide Sidebar

Screening for Alzheimer's Disease: The Memory Impairment Screen (MIS) is more accurate than the 3-word memory test

Screening for Alzheimer's Disease: The Memory Impairment Screen (MIS) is more accurate than the 3-word memory test

Critique date: Mon, 04/26/2004 - 12:43pm
Institution: 
Mount Sinai School of Medicine
   
Article Citation
Citation: 
Kuslansky G, Buschke H, Katz M et al . Screening for Alzheimer's Disease: The Memory Impairment Screen Versus the Conventional Three-Word Memory Test. J Am Geriatr Soc. 2002;50:1086-1091.
   
Clinical Bottom Lines

In community-dwelling older adults, the Memory Impairment Screen more accurately screened for Alzheimer's Disease than the MSSE 3-word memory test:

  • MIS < 4: Sensitivity 86%, Specificity 97%, PPV 0.80, +LR 28.7, -LR 0.14
  • 3 words = 0 recall: Sensitivity 65%, Specificity 85%, PPV 0.37, +LR 4.33, -LR 0.42
   
Methods
Type of Study: 
Diagnostic Test
Setting: 
Einstein Aging Study (Albert Einstein College of Medicine, Bronx, NY)
Patient Population: 

240 community-dwelling older adults (mean age 79 years; 64% women; 72% caucasian; 28% African American; average 12 years education; 12% demented; mean GDS 3.7 for AD, 2.8 for nondemented controls).

Inclusions

over 70 years old, able to understand and perform the requisite experimental tasks. Thus, dementia group consisted mostly of mildly demented individuals.

Intervention/Exposure: 

Cross sectional validation study. Blinded comparison of the MIS and the 3-word accuracy memory test with a comprehensive clinical diagnostic assessment for AD. The MIS and the 3-word memory test were given on different days over 1-2 weeks by different examiners. The MIS was always given first.

Diagnostic tests

The MIS* is a 4-minute, 4 item delayed memory test assessing free and cued word recall (score: 0 to 8). Four words, from four different categories, [checkers (game); saucer (dish), telegram (message), red cross (organization)] are initially read by the subject, and then cued by the examiner until all items are correctly recognized by cue. If a cue is missed, only that cue is provided again. Two to three minutes of interference follows (counting up and down from 1-20 a few times or other tasks) to prevent rehearsal, and then free recall is elicited by asking subject to "Tell me as many of the 4 words you can remember, in any item" over 20 seconds (stop if no more words after 10 seconds elapses). Elicit cued recall of any word NOT retrieved by free recall, e.g., What was the game? Allow 5 seconds for cued responses.  Scoring: 2 points are given for each item obtained by free recall, 1 for each by cued recall. The conventional 3-word memory test is the delayed free recall memory task from the MMSE (score 0 to 3).

Reference standard

AD was diagnosed by case conference consensus with professionals blinded to MIS and 3-word memory tests. Criteria used were DSM-IV and those of the Neurological and Communicative Disorders and Stroke Alzheimer's Disease and Related Disorders Association. Clinical Dementia Ratings (CDRs) were assigned.

Outcome Measures: 

Sensitivity, Specificity, positive predictive values and area under the receiver-operating characteristic (ROC) curves for the MIS and the 3-word memory test. Likelihood ratios were calculated by the MIAH reviewer.

   
Conclusion
Results: 
  • 28 of 240 (12%) community-dwelling older adults were diagnosed with AD.

Test

Sensitivity

Specificity

PPV

+ LR

- LR

MIS score < 4

86%

97%

0.80

28.7

0.14

3-word memory score=0

65%

85%

0.37

4.33

0.42
  • The area under the ROC curves was 0.93 for the MIS and 0.80 for the 3-word memory test.
Concerns Regarding Methodology, Applicability to Older Adults, etc.: 

Comments

  • This is a community based, not a primary care study. Clinic and community samples may vary in composition, with different base rates of dementia, different prevalence of AD, different education ranges, and different languages and cultural backgrounds.
  • Education is unlikely to affect short-term memory therefore the short MIS test comprising free and cued recall may avoid the effects of education on tests scores.
  • Performing the MIS first would increase the learning curve for the 3-word free recall, thus biasing against finding the MIS superior to the 3-word.

Footnote

*Albert Einstein College of Medicine owns the copyright on the MIS and makes this test available as a service to the research community but licenses the test for commercial use.

Funding Source and Role: 
National Institute of Aging and National Institute of Child Health and Human Development
Created By: 
Cinthya Marturano, MD, Second Year Geriatrics Fellow, Mt. Sinai School of Medicine
This is a review of the validity of a single study; the ‘bottom lines’ do not reflect comparison with the rest of the literature on this subject.