Proposed Study of the Effect of Different Subtypes of Cognitive Impairment on the Capacity of Older Individuals to Manage Chronic Disorders

Jim Grigsby (Medicine/Geriatrics, Center forHealth Services Research) Judith Baxter (Preventive Medicine & Biometrics) Angela Brega (Center for Health Services Research) Terry B. Eilertsen (Center on Aging) Richard F. Hamman (Preventive Medicine & Biometrics) Kathryn Kaye (Medicine/Geriatrics, V.A.M.C.) Andrew M. Kramer (Medicine/Geriatrics, Center on Aging) Susan M. Shetterly (Preventive Medicine, Kaiser)

3 Background 65% - 80% of adults over age 65 have chronic health disorders. Ability to manage one’s condition is dependent on integrity of cognitive functioning. High prevalence of cognitive impairment among older adults (15% - 50% or more, with age). It is unclear how, and to what extent, different types of cognitive deficit may affect the capacity for chronic illness self-management. Some chronic illnesses, if poorly controlled, may lead to increased cognitive impairment.

4 Background (Continued) Brain structure and function are organized in a modular fashion, so different cognitive abilities are dissociable. Deficits in a specific ability may affect different specific aspects of functioning. Subtypes of cognitive impairment may require different modes of intervention and approaches to self-management. We are especially interested in the executive cognitive abilities and in the brain’s multiple memory systems.

5 Executive Cognitive Functions A set of higher level cognitive abilities, including: Planning Organization Working memory Self-monitoring (insight) Active problem solving Flexible response to novel situations Capacity to generate information Capacity to use intentions to engage in purposeful activity

6 Executive Cognitive Functions One of the more fundamental executive functions is the ability to use an intention to guide performance of goal-directed behavior. This involves both the ability to initiate purposeful activity independently, and to inhibit irrelevant or inappropriate activity. Persons with such disorders are unable to regulate their own behavior, and require the provision of external structure, encouragement, and supervision. It is likely that they would be unable to manage self- care for chronic illnesses consistently and reliably.

7 Relatively Independent Memory Systems Declarative learning: Information (semantic memory) Events (episodic memory) Hippocampal system Acquired quickly Conscious content, explicit Affected in amnestic syndrome Procedural learning: Learning of skills, habits, and processes Basal ganglia, prefrontal cortex, no hippocampus Acquired slowly Automatic, nonconscious, & implicit Not affected in amnestic syndrome

8 Dissociability of Memory Systems Patient education (i.e., knowledge) often fails to change patient behavior. We suggest this is because declarative (knowledge) and procedural (habit) learning systems are dissociable. Knowledge does not directly affect habits. Habits are difficult to change because they are nonconscious and automatic. Addressing the procedural learning system and helping a patient to acquire new habits may be more effective than providing information for changing self-management behavior.

9 Specific Aims 1. Assess the contribution of different cognitive subsystems to chronic disease self-management. 2. Assess the effectiveness of different management strategies for older persons with chronic illness who have different kinds and degrees of cognitive deficits.

10 Hypotheses We propose to study the role of cognitive impairment in the self-management of type II diabetes among older persons. We intend to test the following hypotheses: 1. Diabetics with executive cognitive deficits will be unable to manage their disease without assistance. 2. Diabetics with prospective memory deficits will not remember to monitor glucose levels or use meds. 3. Providing information and teaching habitual self-care behaviors will yield better outcomes than education alone.

11 Design Population-based, repeated measures cohort design, with a sample of persons age 55 and older who have type II diabetes mellitus. Participants will be assessed at baseline and at 18-month and 36-month follow-up.

12 Outcome Measures Outcome measures include: Glycosylated hemoglobin (HbA1c) Frequency of blood glucose monitoring Frequency and duration of exercise Adherence to diet recommendations Use of insulin

13 Independent Variables Independent variables include: Demographics Comorbidity Capacity to regulate behavior Procedural & declarative learning ability Reasoning ability Mood Self-efficacy

14 Hypothesized Results & Significance Persons with deficient capacity for self-regulation will be unable to manage their care independently, even if they have intact reasoning and declarative memory. These persons will require the active intervention of a caregiver for self-management. Some data suggest uncontrolled DM leads to cognitive impairment. We hypothesize that the rate of cognitive decline will be more rapid for persons who do not have an actively involved caregiver than for those who have such a caregiver present.