Presentation on theme: "A Computerized/Web-Based Test to Assess the Continuum of Normal Memory/Cognition to Dementia J. Wesson Ashford, M.D., Ph.D. Stanford/VA Aging Clinical."— Presentation transcript:
A Computerized/Web-Based Test to Assess the Continuum of Normal Memory/Cognition to Dementia J. Wesson Ashford, M.D., Ph.D. Stanford/VA Aging Clinical Research Center Palo Alto, California American Association of Geriatric Psychiatry March 6, 2009
Need for Mass Screening Alzheimers disease, dementia, and memory problems are difficult to detect when they are mild There are important accommodations and interventions that should be made when there are cognitive impairments –(like needing glasses or having driving restrictions if you have vision problems)
Issues for Memory Screening Current testing for memory problems is based on having a tester sit in front of a subject for a prolonged period of time and administer unpleasant tests Testing must be –Inexpensive (minimal need for administrator) –Fun (so people will return for frequent testing) –More precise, reliable, and valid To improve sensitivity To improve specificity
Audience Screening Presentation of complex pictures (that are easily remembered normally) are useful for detecting memory difficulties Testing memory using a pictures approach needs standardization for population use Picture memory is less affected by education Picture memory can be tested by computer Audiences can be shown slide presentations
IRB FORM (exempt) Screening for Memory Problems Information Sheet Description: You are invited to participate in a research study of memory and aging. You will take a memory test that involves looking at a number of pictures and indicating which are duplicated. You may also be asked to remember a list of words, or to take other brief memory tests. If the results of these tests indicate that you may have some memory concerns, we may offer you the opportunity to participate in more detailed memory studies. For Questions About This Study: If you have any questions about this study, please contact: Dr. Wes Ashford, Aging Clinical Research Center, 3801 Miranda Avenue (151Y), VA Palo Alto Health Care System, Palo Alto, CA 94304, (650) 852-3287. Purpose: This is a research program to screen for memory problems. Information we collect about you will be added to information about other people and analyzed to help researchers and clinicians better understand how memory changes with aging. The results of this research study may be presented at scientific or medical meetings or published in scientific journals. However, personal information or your identity will not be disclosed. Your participation in this research study will take approximately 30 minutes to one hour. Participation is Voluntary: If you have read this form and have decided to participate in this project, please understand your participation is voluntary and you have the right to withdraw your consent or discontinue participation at any time without penalty or loss of benefits to which you are otherwise entitled. You have the right to refuse to answer particular questions. Your individual privacy will be maintained in all published and written data resulting from the study. Independent Contact: If you are not satisfied with the manner in which this study is being conducted, or if you have any concerns, complaints, or general questions about the research or your rights as a research study subject, please contact the Stanford Institutional Review Board (IRB) to speak to an informed individual who is independent of the research team at (650)-723- 5244 or toll free at 1-866-680-2906. Or write the Stanford IRB, Administrative Panels Office, Stanford University, Stanford, CA 94305-5401.
Demographic Information (front of sheet) (circle, check, or fill in answers) Month of Birth: Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Year of Birth: 19 _____ ____ Gender:Male __________ Female__________ Education Level (number of years): ________ 1 Elementary (0-6)2 Jr. High School (7-8) 3 High School (12) 4 Some College (13-15) 5 AA Degree (14)6 Bachelors Degree (16) 7 Masters Degree (18)8 PhD, MD, JD (20+)9 Other or unknown Veteran Status: Vet_____ NonVet______ Unknown_____ Occupation: _______ 1 Never employed2 Student3 Homemaker 4 Unskilled/semiskilled 5 Skilled trade/craft6 Clerical/office Worker 7 Manager Business/Gov8 Professional/Technical9 Other or Unknown Employment Status: Full Time____ Part Time____ Unemployed____ Retired____ Primary Race: __________ 1 White2 Black or African American 3 American Indian or Native Alaskan4 Native Hawaiian or other Pacific Islander 5 North Asian (i.e., China, Japan)6 Middle East/South Asian 7 More than one race8 Decline to state 9 Unknown Hispanic Ethnic Background? No____ Yes____ Unknown____ Have you had problems with your memory recently? Yes_______ No__________
Answer Sheet for Memory Screening (back of sheet) Carefully look at each picture. If you see a picture that you have seen before, mark the circle next to the number of the repeat picture. For the main test, you will see 50 pictures. Each picture is numbered. The pictures will stay on the screen for 5 seconds. 25 pictures are new, 25 pictures are repeated.
Selection of Subjects for Analysis about 50Eliminated subjects - about 50 –20 had marks that were un-interpretable –31 were below chance (12/25 or less) on the true negative or true positive score True-: 3 males, 10 femalesTrue-: 3 males, 10 females True+: 8 males, 11 femalesTrue+: 8 males, 11 females Included subjects - 1018
Group Size AGE (years) Gender m/f Ed (years)True-%True+% #reports 10189719479411018 Mean39/site74.6295/6521690.2%92.3% St Dev3413.82.510.3%13.7% Range9 - 14220-986-2150-100 Study Population Includes only subjects who performed non-randomly on the test (1018) - # of reporting individuals 7/11/2007 – 8/14/2009 at 26 sites - (not all subjects answered every question) 805 reported being white 31 reported they were less than 40y/o
Test Performance for 1018 subjects 82 (8%) had perfect scores,82 (8%) had perfect scores, 230 (23%) made 1 error (98% correct),230 (23%) made 1 error (98% correct), 700 (69%) made 5 or fewer errors (>90% correct),700 (69%) made 5 or fewer errors (>90% correct), 132 (13%) made 6 – 10 errors (80 – 88% correct),132 (13%) made 6 – 10 errors (80 – 88% correct), 186 (18%) made > 10 errors ( 10 errors (<80% correct).-------------------------------------------------------------------- 70 (7%) scored < 80% correct for True Negatives70 (7%) scored < 80% correct for True Negatives –19 (6%) males, 51 (8%) females (false positive responses = saying a picture is repeated when not),(false positive responses = saying a picture is repeated when not), 79 (8%) scored < 80% correct for True Positives79 (8%) scored < 80% correct for True Positives –25 (7%) males, 54 (8%) females (false negative responses = failure to recognize/recall repeat picture).(false negative responses = failure to recognize/recall repeat picture).
Key to Plots Plots are shown for the 858 individuals with age, gender, education data,Plots are shown for the 858 individuals with age, gender, education data, First plot shows responses by item (1 - 50)First plot shows responses by item (1 - 50) –Red is first presentation (no mark required), –Green is repeat (mark required), Second plot shows performance by genderSecond plot shows performance by gender –Males in blue, –Females in pink
Plots of Performance by Age for each Gender Percent correct, linear-linear plot Percent incorrect, linear-linear plot Percent incorrect, log-linear plot captures a greater proportion of the variance than the linear – linear plots – consistent with an exponential increase of failures with age – as predicted by the Gompertz Law Note scores less than 20 indicate less than 80% correct for that aspect of performance.
Summary of Findings There is minimal difference in performance of individual items between males and females, in spite of significant male-role and female-role items. There is a significant decline of function with age on both aspects of the test, with the age-effect best explained by an exponential increase of errors with age (Failure Theory). Females had a greater association of false-positive errors with age than males, while the false-negative error association with age was similar by gender. Education was not significant in performance
Implications of Findings MemTrax is a brief, convenient, fun, audience-pleasing test of the type of complex memory affected by Alzheimer pathology –an audience-voting system is needed (can also do web or computer-base) Recognition failure (False-) indicates failure of learning circuits –typical of Alzheimers disease memory difficulty 80 – 88% correct is suggestive of early, mild memory problems less than 80% suggests impairment of function consistent with dementia False-recognition (False+) responses are indicative that the subject is not paying attention and is failing to inhibit the recognition response –suggests other types of psychopathology: e.g., fronto-temporal dementia MemTrax can test many levels of memory impairment –but need to establish accuracy, validly, and reliability Alzheimers disease is not a dichotomous diagnosis but a continuum of impairment best assessed probabilistically using Item Response Theory (Modern Test Theory), requiring gradation of an individuals function –such testing is an excellent approach for the longitudinal automated assessment
Acknowledgements Pictures courtesy of Henry Bowles, of Bowles-Langley Technology Audience performance measurements coordinated by Emily Gere and associates Presentations coordinated by Deryl Wicks Data entry by Drs. Raj Sharma, Samina Gul Presentations under the auspices of the Stanford/VA Aging Clinical Research Center and approved by Stanford and VA IRBs
Tests Available On-Line www.medafile.com www.memtrax.net/BLT www.cogolog.com www.cognitivelabs.com www.ibaglobal.net/BLT For further information, contact: –Wes Ashford: firstname.lastname@example.org