Conducting Research in Those with Cognitive Impairments 101

Transcription

1 Conducting Research in Those with Cognitive Impairments 101 Kevin Duff, PhD Department of Neurology Center for Alzheimer s Care, Imaging, & Research University of Utah 11/8/12 Center for Alzheimer s Care, Imaging and Research (CACIR)

2 Objectives 1. Review states of cognitive impairment 2. Summarize approaches to conducting research in cognitively impaired cohorts 3. Discuss policies and procedures at use in Utah

3 Cognitive status among older adults Mayo Clinic Study of Aging

4 Many types of dementia

5 Does a diagnosis of Alzheimer s disease mean that someone does not have the capacity to provide informed consent? NO diagnosis tells you little about decisional capacity

6 Capacity in Cognitively Impaired 25 40% of mild to moderate stage AD patients were judged to have adequate capacity to provide consent (Karlawish et al., 2005; Warner et al., 2008) 60% of MCI patients were judged to have adequate capacity to provide consent (Jefferson et al., 2008) Palmer et al. (in press): AD patients 60% had capacity to appoint a proxy 43% had capacity to consent to drug trial 16% had capacity to consent to neurosurgical trial Variability in judging capacity can be very wide, even among experienced psychiatrists and geriatricians 0 100% agreement in some studies

7 Common approaches for obtaining consent in the cognitively impaired

8 Alternate approaches for obtaining consent 1. MacArthur Competence Assessment Tool (MacCAT; Appelbaum & Grisso, 2001) Semi structured interview assessing Understanding of study specific info Appreciation of impact on individual Reasoning (weighs pros and cons) Expression of Choice Ratings made by examiner Flexible (simple vs. complex, treatment vs. clinical research)

9 Alternate approaches for obtaining consent 2. Evaluation to Sign Consent (DeRenzo et al., 1998) Quicker, more practical than MacCAT, but less detailed, informative Following review of consent document, examiner assesses Alert and able to communicate Name 2 risks of participating Name 2 things he/she will be expected to do How to stop participating How to express distress/discomfort Modified version used for most CACIR studies

10 If someone lacks capacity, does that mean that he/she cannot participate in research? NO Capacity to provide consent is only one route into research

11 Retaining some autonomy Kim et al. (2002) Even with decreased decisional capacity, patients with AD similarly judged risk in hypothetical scenarios compared to healthy elderly AD patients with higher decisional capacity were more likely to agree to participate in studies than those with lower decisional capacity (i.e., low decisional capacity does not increase willingness to participate in trials)

12 Alternate avenues into research 1. Legally authorized representatives (LARs) Individual who provides consent on behalf of the subject Spouse, adult child, power of attorney, guardian Many patients retain ability to designate a research proxy (even if they lack capacity to provide consent) 2. Assent Verbal or written agreement to participate in research Paramount to LAR s consent Yet, this remains a poorly defined concept and lacks specific procedures

13 Alternate avenues into research 3. Improving decisional capacity Moser et al. (2006) Patients with schizophrenia reviewed a fictional consent document and took MacCAT Viewed PowerPoint presentation about study and discussed each aspect of MacCAT with < max. credit Patients with < max. credit showed significant improvement on MacCAT following intervention

14 Distinction of decisional impairment vs. cognitive impairment Must be rationale for including decisional impaired subjects Excluding subjects solely based on cog imp is discriminatory and does not allow for an equitable selection of subjects Use of cog imp subjects must fall into 1. Minimal risk 2. >Min. risk but also chance of direct benefit 3. >Min. risk & no direct benefit but generalizable knowledge of disorder

15 Investigators are responsible for describing procedures to evaluate decisional capacity, psychiatric consult may assist Decisional capacity can fluctuate across time, so needs to be re evaluated Advanced informed consent with proxy can be used if decisional capacity is expected to decline

16 Final Thoughts Decisional capacity and enrollment in studies involves multiple factors, including Participant factors (education, cultural, level of cog imp, stress/mood, other conditions, meds) Situational factors (support) Study factors (complexity, risks/benefits) If you enroll only highly capable AD patients, then will results of clinical trial generalize to other AD patients?