Improved Treatment of Ischemic Heart Disease and Disability and Death in the Elderly Kate Stewart Mary Beth Landrum David Cutler Academy Health June 27, 2006

Background Changes in health/disability among population aged 65+ over the past 20 years: Changes in health/disability among population aged 65+ over the past 20 years: Prevalence of chronic diseases increased Prevalence of chronic diseases increased Disability decreased Disability decreased

Background Does medical care explain some of the disability decline? Does medical care explain some of the disability decline? Focus: Ischemic Heart Disease Focus: Ischemic Heart Disease Prevalence increases with age Prevalence increases with age Medical advances reduced mortality by 40-66% between Medical advances reduced mortality by 40-66% between Clinical trials: improved survival and quality of life Clinical trials: improved survival and quality of life Little understanding of effect of improved treatment on population disability Little understanding of effect of improved treatment on population disability

Data: National Long Term Care Survey Medicare-linked data: hospitalizations & vital status Medicare-linked data: hospitalizations & vital status Analytic Cohort: IHD hospitalization Health Status at Follow-Up Disabled Dead Alive & Non-Disabled N = 54,453 Baseline Survey N = 3,842

Data: Medical Treatment Cardiovascular Cooperative Project (CCP), Cardiovascular Cooperative Project (CCP), Share of appropriate AMI patients within a hospital referral region (HRR) who received Share of appropriate AMI patients within a hospital referral region (HRR) who received Aspirin Aspirin Ace-Inhibitors Ace-Inhibitors Beta Blockers Beta Blockers Reperfusion within 12 hours after AMI Reperfusion within 12 hours after AMI Invasive procedures variable Invasive procedures variable Share of respondents with procedures on the heart, pericardium or vessels of the heart Share of respondents with procedures on the heart, pericardium or vessels of the heart

Analytic Strategy Evaluate whether IHD patients living in HRRs with more intensive treatment had better outcomes Evaluate whether IHD patients living in HRRs with more intensive treatment had better outcomes Minimize selection problems Minimize selection problems Natural experiment Natural experiment Exposure = treatment intensity Exposure = treatment intensity Estimate decline in disability attributable to improved treatment Estimate decline in disability attributable to improved treatment Simulate health outcomes by varying levels of care Simulate health outcomes by varying levels of care

Multinomial Models Model 1: Y = Xβ + λ 1 Year89 + λ 2 Year94 Model 1: Y i,j,t = X i,t β + λ 1 Year89 + λ 2 Year94 Model 2: Y = Xβ + λ 1 Year89 + λ 2 Year94 + Model 2: Y i,j,t = X i,t β + λ 1 Year89 + λ 2 Year94 + γCCP Tx + δCCP Tx*Year + τProcs γCCP Tx j + δCCP Tx j *Year + τProcs j

Results: Multinomial Models Model 1: Without Tx*Model 2: With Tx* Disabled vs. Non- Disabled Dead vs. Non- Disabled Disabled vs. Non-Disabled Dead vs. Non-Disabled Odds Ratios λ λ 1 : Year # λ λ 2 : Year # 0.60 # Joint F-test: treatments -- P <0.01 *1984 is reference year # p <0.05 ^ ^ ^

Results Simulations by percentiles of care: Number alive & non-disabled relative to observed Simulations by percentiles of care: Number alive & non-disabled relative to observed

Limitations Potential unmeasured confounding: Potential unmeasured confounding: Area-level treatment variables Area-level treatment variables Changes in severity of hospital admissions over time Changes in severity of hospital admissions over time Differences in claims coding over time Differences in claims coding over time CCP treatment variables measured at 1 time point only CCP treatment variables measured at 1 time point only

Conclusions Elderly IHD patients were more likely to be alive & non-disabled over time Elderly IHD patients were more likely to be alive & non-disabled over time Increased treatment explains approx. 50% of the disability decline Increased treatment explains approx. 50% of the disability decline 21% more elderly IHD patients would have been alive and non-disabled in 1999, if all lived in high treatment areas 21% more elderly IHD patients would have been alive and non-disabled in 1999, if all lived in high treatment areas Improved care and outcomes possible through increased use of appropriate IHD treatments Improved care and outcomes possible through increased use of appropriate IHD treatments

Funding Funding: Funding: National Institute on Aging (P30 AG12810 and R01AG019805) National Institute on Aging (P30 AG12810 and R01AG019805) Mary Woodard Lasker Charitable Trust Mary Woodard Lasker Charitable Trust Michael E. DeBakey Foundation Michael E. DeBakey Foundation

Results: Health Status at Follow-Up *p-value calculated from pearson chi-square test of independence, corrected for the complex survey design. Estimates adjusted to the age and sex distribution of the 1999 population of Medicare beneficiaries Difference p-value* % Disabled % Dead % Alive & Non- disabled

Area-Level Treatment Percent Invasive Procedures Percent Invasive Procedures 10 th percentile: 6% in 1984 and 18% by th percentile: 6% in 1984 and 18% by th percentile: 40% in 1984 and 70% by th percentile: 40% in 1984 and 70% by 1994 Percentiles of Care: 10 th 90 th Beta Blockers Ace-Inhibitors Aspirin Reperfusion CCP Measures