Presentation on theme: "MemTrax (Computerized Memory Screen) American Association of Geriatric Psychiatry (AAGP) March 2, 2007 J. Wesson Ashford, M.D., Ph.D. Stanford / VA Aging."— Presentation transcript:
MemTrax (Computerized Memory Screen) American Association of Geriatric Psychiatry (AAGP) March 2, 2007 J. Wesson Ashford, M.D., Ph.D. Stanford / VA Aging Clinical Research Center & Alzheimer Center www.medafile.com COLLABORATORS MEMTRAX Henry Bowles, Ted Langley (Bowles-Langley Technology) Paul Costa (Internet Broadcasting Association) Michael Addicott (Cognitive Labs) Emily Gere (Stanford / VA Aging Clinical Research Center)
MMSE information according to time into Alzheimer’s disease
Problems with the MMSE Mini-Mental State Exam – no psychometrics –Folstein et al., 1975 (antique) Considerable noise Several items do not provide adequate information Poor range for measuring change –Large standard error of measurement Poor power for assessing medication benefit Inadequate screening tool Better, shorter tests are available Now, copyright is being enforced (not free!!)
Time to Administer Available Short Screening Tests MMSE 10 -- 15 min Too long 7-Minute Screen 7 – 10 min Too complex Clock Drawing Test 2 – 4 min Not sensitive Mini-cog 3 – 5 min Complex scoring, unclear adequacy Memory Impairment Screen 4 min Need for slightly shorter, easier test (a highly accurate test that takes less than 2 min is not available)
$W = Cost–Worthiness Calculation I = incidence (new occurrences each year, by age) $T = cost of test, time to take (Subject, Tester) Se = sensitivity of test = True positive / I Sp = specificity of test = True negative / (1-I) Cost: –$B = benefit of a true positive diagnosis Estimate: (100 years – age ) x $1000 Save $50,000 NH cost / 1year (after treatment cost deduction) –$C = cost of a false positive diagnosis $500 for further evaluation (time, stress of suspecting dementia) –True negative (real peace of mind) (no money) –False negative = false peace of mind (no price) $W = ($B x I x Se) – ($C x (1-I) x (1-Sp)) - $T Kraemer, Evaluating Medical Tests, Sage, 1992
MEMTRAX - Memory Test (For Dementia Screening, Cognition Assessment) Test to screen patients for dementia, AD: –Computerized test (computer or web - 3 minutes) –KIOSK administration (clinic check-in) –Group administration (Power-Point – 5 minutes) Estimate level (based on 200 patients, caregivers) –>90% very good –80-90% good –70-80% consider mild cognitive impairment –<70% dementia Test can be repeated often (e.g., quarterly) Any change over time can be detected Test is at: www.medafile.comwww.medafile.com
MEMTRAX Memory Test (Power-Point Presentation) (need 50 point answer sheet to hand out) On the paper & pencil version, each slide is shown for 5 seconds. The test-taker is ask to fill in the circle next to the number for a repeated slide. The 50-slide test takes 4 minutes and 10 seconds.
116 Subjects Took This Version Participants at 7 Talks about Alzheimer’s Disease Study approved by Stanford/VA IRB All testing done anonymously AGE (years) Education (years)GenderGroup Size Mean701630 female16 StDev12.22.625 male8 Range25-9914 - 2745% male4-26 Number reporting1037755
249 - False Positive Responses for Each Slide, by Slide Number Order (116 subjects voluntarily participating at local informational talks)
242 - False Positive Responses by Slide Number, by Number of Errors (116 subjects voluntarily participating at local informational talks)
249 - False Negative Responses for Each Slide, by Slide Number Order (116 subjects voluntarily participating at local informational talks)
249 - False Negative Responses for Each Slide, by Number of Errors (116 subjects voluntarily participating at local informational talks)
MEMTRAX Memory Test 116 subjects – mostly elderly normals, some young, some dementia patients False positive errors (false recognition) – 33(64);6(58);47(27)—4,18,23,34(1);1,2,8(0) - mean – 8.3% (sd-14.5%) errors per item False negative errors (failure to recognize) – 35(33);27(20);5(16)—32(4);24(3);45(3) - second presentation (#15): mean- 10.5% (sd-6.2%) errors per item - third presentation (#10) mean – 5.7% (sd-2.5%) errors per item - second 10 vs. same third 10: 10.5% (sd-3.4%) vs 6.6% (sd-2.5%)
Percent of Sample Errors # missedFalse PositiveFalse NegativeTotal Errors Cummulative for total errors 018%34%7% 128%30%16%22% 218%12%14%36% 321%9%17%53% 49%7%20%73% 53%2%4%78% 61%5%83% 72%4%87% 82% 6%93% >81%3%7%100% More than 5 false positive errors (<80% correct) may suggest frontotemporal dementia More than 5 false negative errors (<80% correct) may suggest Alzheimer type dementia
Shows false negative errors increase with age at a greater rate than false positive errors.
Shows that the first repeat image is recognized less reliably than the second repeat. The deficit in first repeat image recognition increases more steeply with age.
CONCLUSIONS on MEMTRAX A short, computerized test provides a measure of cognitive function, including memory and attention, on a robust continuum, establishing a baseline of cognitive function and potentially predicting the presence of dementia –Computerized version – 2-3 minutes, fun game, provides reaction time measure –Paper&Pencil, with PowerPoint slide show, can be given to a large audience Testing for reliability and validity are Classical Test Theory concepts –Modern Test Theory examines performance across individual items on a continuum (varied by first repeat vs second repeat, number of slides between first show and first repeat, etc. –Analysis for maximum likelihood level of cognition (both recognition and attention), provides information about dementia probability –Information about visuo-spatial and language function is available The test can be extended: –if an individual performs poorly, test difficulty can be reduced and further testing can improve the information for predicting dementia presence –For higher functioning subjects, further testing can be made more difficult and give an estimation of current level that can be monitored for change –Unlimited comparable test versions can be developed for longitudinal assessment This suitably short screen can be administered yearly to individuals over 60 y/o as a 6 th vital sign in a clinicians office or at a community health fair –False negatives (biggest failure to recognize first repeat) suggests Alzheimer type dementia –False positives (over recognition) suggests fronto-temporal type dementia
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