1. 1 Patient Dependence, Function, and Changes in Cost of Care in Alzheimer’s Disease Carolyn W. Zhu JJP VA Medical Center, Mount Sinai School of Medicine Academy Health June 10, 2008

2. 2 Collaborators Christopher Liebman Elan Pharmaceuticals Trent McLaughlin Elan Pharmaceuticals Nickolas Scarmeas Columbia University Medical Center Marilyn Albert Johns Hopkins University Jason Brandt Johns Hopkins University Deborah Blacker Harvard Medical School Mary Sano Mount Sinai School of Medicine Yaakov Stern Columbia University Medical Center

3. 3 Background Alzheimer’s disease (AD) is characterized by impairment in cognition, function, and behavior Cost of care for patients with AD are significantly associated with functional impairment Functional impairment may not fully represent patients’ overall dependence on other individuals Functional impairment provides partial explanation of variation in AD related costs

4. 4 Background (cont.) Dependence Scale (DS) was developed to directly measure the amount of assistance AD patients need DS measured related but distinct aspects of disability in AD Information on the relationship between DS and healthcare cost is limited

5. 5 Objectives To examine the relationship between patients’ dependence and function on cost of care at baseline and longitudinally To compare strengths of their relationships with different cost components

6. 6 Dependence Scale Sample Questions A.Does the patient need reminders or advice to manage chores, do shopping, cooking, play games, or handle money? B. Does the patient need help to remember important things such as appointments, recent events, or names of family or friends? L. Does the patient wear a diaper or a catheter? M. Does the patient need to be tube fed?

7. 7 Methods: Sample Design –Prospective study with up to 7 years of annual follow-up Setting –Three University-based AD centers in the US Subjects –Met DSM-III-R criteria for primary degenerative dementia of the Alzheimer type and NINDS-ADRDA criteria for probable AD –Modified Mini-Mental State Examination (mMMS) ≥30 at enrollment –Visits during which patient was living in nursing home excluded

8. 8 Methods: Dependent Variables Direct medical cost -Hospitalizations, assistive devices, outpatient tests and procedures, medications Direct non-medical cost -Home health aides, respite care, adult daycare Informal cost -Cost of informal caregivers’ time for basic and instrumental activities of daily living (BADL and IADL) -Up to three caregivers’ time included Costs adjusted to 2005 constant dollars

9. 9 Methods: Independent Variables Main independent variables –Dependence: Dependence Scale (DS) –Function: Blessed Dementia Rating Scale (BDRS) Other clinical variables –Mini-Mental State Examination (MMSE) –Presence of psychotic symptoms, behavioral problems, depressive symptoms, extrapyramidal signs –Number of comorbidities Demographic variables –age, sex, race/ethnicity, education, site

10. 10 Methods: Analysis Baseline analysis: Generalized linear models with gamma distribution and identity link Longitudinal analysis: Generalized linear mixed models

11. 11 Methods: Analysis (cont.) Two sets of models estimated for each analysis -Full model: DS, BDRS, all other covariates -Trimmed model: DS, BDRS, demographics, site Varied wage rates -National average hourly earnings for all private industries -National average wage for home health aides

12. 12 % female58 Age, mean (sd) 76 (8) % White96 Years of schooling, mean (sd)14 (3) % Married67 Results: Baseline Demographics

13. 13 Results: Baseline Clinical Characteristics Dependence Scale (0-15), mean (sd)5.1 (2.3) Blessed Dementia Rating Scale (0-17), mean (sd) 3.5 (2.1) Mini-Mental State Examination (0-30), mean (sd)22.1 (3.6) # Comorbidities, mean (sd)0.8 (0.9) % Behavior problems41.6 % Psychotic symptoms30.2 % Depressive symptoms20.5 % Extrapyramidal signs14.5

14. 14 Results: Baseline Healthcare Use Number of hospitalizations, mean (sd)0.3 (0.6) Number of outpatient treatments/procedures, mean (sd) 2.0 (2.1) Number of assistive devices, mean (sd)1.2 (1.1) Number of medications, mean (sd)3.8 (1.5) Informal hours per week, mean (sd)20.7 (24.0)

15. 15 Results: Medical and Non-medical Cost by Dependence Scale

16. 16 Results: Informal Caregiving Time by Dependence Scale

17. 17 Results: Baseline Analysis * p<0.05 Direct Medical Cost coef. (se) Informal Cost coef. (se) DS$298 (408)$1,690 (749)* BDRS$1,406 (702)*$1,941 (1,458)

18. 18 Results: Longitudinal Analysis ** p<0.01 * p< 0.05 Direct Medical Cost Direct Non- medical Cost Informal Caregiving Time DS5.7%**10.5%*4.1%** BDRS7.6%*3.8%**8.7%**

19. 19 Conclusions Both dependence and functional impairment are significantly associated with higher costs of care Dependence and function relate differently to different components of costs Small changes in dependence and function are related to large changes in healthcare costs Relationship observed at baseline is consistent over time

20. 20 Limitations Sample may represent a nonrandom sample of AD patients in the community Estimated costs are costs associated with caring for patients with AD, not incremental costs due to AD

21. 21 Implications Dependence and function provide unique information in explaining variations in cost of care in AD Interventions that enhance patient independence (or delay patients moving to a higher level of dependence) may be associated with cost savings