Instruments for the early detection of dementia in persons with intellectual developmental disorder
Elisabeth L. Zeilinger, Katharina A.M. Stiehl, Germain Weber University of Vienna, Faculty of Psychology, Austria
22nd Alzheimer Europe Conference 04.- 06.10. 2012 Changing perceptions, practice and policy Vienna, Austria OUTLINE
1. Background – Intellectual developmental disorder (IDD) – Dementia and IDD – Assessment-instruments for dementia in persons with IDD
2. Method – Systematic review
3. First results and further steps
4. Conclusion Intellectual developmental disorder (IDD)
3 criteria for diagnosis (AAIDD, 2010): 1. Limitations in intellectual functioning (IQ < 70) 2. Limitations in adaptive behavior 3. The disability originates before the age of 18
Life expectancy (Carter & Jancar, 1983; Strauss & Eyman, 1996) • 1930: ca. 20 years • 1980: ca. 58 years • 1996: ca. 72 years • 2000: mild IDD: nearly like general population severe IDD: reduced (Bittles et al., 2002; Patja et al., 2000)
Challenge for the health care system Dementia becomes a more problematic health risk
Dementia in persons with IDD - Prevalence
No consistent estimates available!
. 11,4% > 50 years (Moss, 1997) . 22% > 65 years (Lund, 1985)
. Persons with trisomy 21: . 50+ years: 42% (Haveman,1997) . 60+ years: 26% (Coppus et al., 2006) 42% (Tyrrell et al., 2001) 56% (Haveman,1997) . 70+ years: 100% (Visser et al, 1997) Dementia in persons with IDD - Symptomatology
Symptomatology differs from general population . Behavioral changes are frequent and early (often before cognitive changes) . Low pre-morbid cognitive level hinders identification of cognitive changes . „diagnostic overshadowing“ . Reduced life expectancy (especially in specific syndromes) Onset of dementia earlier than in the general population
Dementia in persons with IDD - Assessment
Assessment (screening and diagnosis) has to be adapted . Instruments (e.g. MMSE, CERAD) for the general population are not suitable for persons with IDD Norms / cut-offs from general population not usable
There are various ID specific instruments: . Cognitive tests . Rating scales for person with IDD . Rating scales for 3rd persons
Assessment instruments
Instruments for assessing dementia differ in many aspects: • Descriptive aspects • Purpose: e.g. assessing behavioral changes or assessing cognitive decline • Respondents: PwIDD, 3rd person, health professional • Level of IDD, • …. • Quality aspects • Psychometric properties: Reliability, validity, feasibility, … • Measurement characteristics: Floor/ceiling effects, responsiveness, …
What is the most appropriate instrument for the intended purpose and how to find it? Which instruments are available? What are their characteristics? What kind of evaluations have been done?
Systematic overview of available instruments and their characteristics
Helps to find and choose an adequate instrument more easily and evidence based For researchers, professionals, carers, ..
Enables a better (early) detection of dementia in persons with IDD
Missing instruments/evaluations become obvious E.g. ROM (routine outcome measurement) for severe IDD E.g. no validation for frequently used instrument Systematic literature review
• in 5 databases: CINAHL, PsycInfo, PubMed, Scopus, Web of Science
• Inclusion-criteria: − development or evaluation of a screening instrument for dementia − especially developed or adapted for persons with IDD
• Exclusion-criteria: − no medical tests (e.g. genetic marker tests, PET, fMRI) Search strategy
1 2 3 Population Concept Output
Search Intellectual developmental disorder Dementia Assessment instruments terms
intellectual disability; mental retardation; assessment; diagnostic; diagnosis; mental handicap; learning disability; dementia; Alzheimer’s screening; instrument; tool; Synonyms mental deficiency; developmental disability; disease measurement; questionnaire; trisomy 21, down syndrome psychometrics; scale; interview
((intellectual* OR mental* OR learning OR assess* OR diagnosti* OR screen OR Combines developmental*) AND (disab* OR retard* dement* OR screening* OR instrument* OR tool* and OR handicap* OR deficien*)) OR trisom* Alzheimer* OR measure* OR questionnaire* OR truncated 21 OR (down* AND syndrom*) psychometr* OR scale* OR interview*
• Search string: 1 AND 2 AND 3; in title, abstract und keywords • No limits were set (language, year,..) First results & future steps
IDD Trisomie 21 n = 3036 n = 1587
GOAL: All studies evaluating duplicates n = 4623 dementia instruments n = 1828
title-/abstract screening n = 2795 n = 2661
2nd search: full-text cited.referende search of full-text screening original papers n = ? n = 88
instruments found relevant papers n = ? n = ? Coding with CAPs-IDD
(Characteristics of Assessment Instruments for Psychiatric Disorders in Persons with Intellectual Developmental Disorders)
I Conceptual and Measurement Model Mostly Section B: Basic Information IDD-specific Section T: Test development and theoretical foundation Section C: Measurement characteristics II Psychometric Properties Section V: Validity
Section R: Reliability Mostly not Section O: Objectivity of Application IDD-specific Section N: Objectivity of Interpretation, Norming and Fairness Section F: Feasibility Conclusion
• Systematic overview and description of available instruments Simplifies: Finding adequate instruments Simplifies: Direct comparison of instruments Simplifies: Choosing instrument, that best fits the intended purpose best (evidence based)
• Which instruments are missing • Which evaluations of instruments are missing Need for future research becomes visible
• Using suitable instruments > better (early) detection of dementia in persons with IDD
Contact:
Elisabeth L. Zeilinger Tel: +43 - 1- 4277- 471 24 Mail: [email protected]
Katharina A.M. Stiehl Tel: +43 - 1- 4277- 478 96 Mail: [email protected]
Germain Weber Tel: +43 - 1- 4277- 472 24 Mail: [email protected]