Improved Improved Treatment of Treatment of

Ischemic Heart Ischemic Heart Disease and Disease and

Disability and Disability and Death in the Death in the

ElderlyElderlyKate StewartKate Stewart

Mary Beth LandrumMary Beth Landrum

David CutlerDavid CutlerAcademy Health

June 27, 2006

BackgroundBackground

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

increasedincreased Disability decreasedDisability decreased

BackgroundBackground

Does medical care explain some Does medical care explain some of the disability decline?of the disability decline? Focus:Focus: Ischemic Heart Disease Ischemic Heart Disease

Prevalence increases with agePrevalence increases with age Medical advances reduced mortality by Medical advances reduced mortality by

40-66% between 1968-200040-66% between 1968-2000 Clinical trials: improved survival and Clinical trials: improved survival and

quality of lifequality of life Little understanding of effect of Little understanding of effect of

improved treatment on population improved treatment on population disabilitydisability

Data: Data: National Long Term Care National Long Term Care

SurveySurvey Medicare-linked data: hospitalizations & vital Medicare-linked data: hospitalizations & vital

statusstatus

Analytic Cohort:

198919941999

198419891994

IHD hospitalization

Health Status at Follow-Up • Disabled• Dead• Alive & Non-Disabled

N = 54,453

Baseline Survey

N = 3,842

Data: Medical TreatmentData: Medical Treatment

Cardiovascular Cooperative Project Cardiovascular Cooperative Project (CCP), 1994-1995(CCP), 1994-1995 Share of appropriate AMI patients Share of appropriate AMI patients

within a hospital referral region (HRR) within a hospital referral region (HRR) who receivedwho received AspirinAspirin Ace-InhibitorsAce-Inhibitors Beta BlockersBeta Blockers Reperfusion within 12 hours after AMI Reperfusion within 12 hours after AMI

Invasive procedures variable Invasive procedures variable Share of respondents with procedures Share of respondents with procedures

on the heart, pericardium or vessels of on the heart, pericardium or vessels of the heartthe heart

Analytic StrategyAnalytic Strategy

Evaluate whether IHD patients Evaluate whether IHD patients living in HRRs with more intensive living in HRRs with more intensive treatment had better outcomestreatment had better outcomes Minimize selection problemsMinimize selection problems Natural experimentNatural experiment

Exposure = treatment intensityExposure = treatment intensity Estimate decline in disability Estimate decline in disability

attributable to improved attributable to improved treatmenttreatment

Simulate health outcomes by Simulate health outcomes by varying levels of carevarying levels of care

Multinomial ModelsMultinomial Models

Model 1: YModel 1: Yi,j,t = X = Xi,tββ + + λλ11Year89 + Year89 + λλ22Year94 Year94

Model 2: YModel 2: Yi,j,t = X = Xi,tββ + + λλ11Year89 + Year89 + λλ22Year94 + Year94 +

γγCCP TxCCP Txj + + δδCCP TxCCP Txj*Year + *Year + ττProcsProcsj

Results: Multinomial Results: Multinomial ModelsModels

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 Odds Ratios

λλ 1: Year890.83 0.77# 0.90 0.91

λλ 2: Year940.70# 0.60# 0.83 0.85

Joint F-test:treatments

- - P <0.01 P <0.01 P <0.01P <0.01

*1984 is reference year

#p <0.05

^^

^

ResultsResults Simulations by percentiles of Simulations by percentiles of

care: Number alive & non-care: Number alive & non-disabled relative to observeddisabled relative to observed

-400

-300

-200

-100

0

100

200

300

1984 1989 1994

No

. Eld

erl

y (

00

0's

)

10th

90th

LimitationsLimitations

Potential unmeasured Potential unmeasured confounding:confounding: Area-level treatment variablesArea-level treatment variables Changes in severity of hospital Changes in severity of hospital

admissions over timeadmissions over time Differences in claims coding over Differences in claims coding over

timetime CCP treatment variables CCP treatment variables

measured at 1 time point onlymeasured at 1 time point only

ConclusionsConclusions Elderly IHD patients were more Elderly IHD patients were more

likely to be alive & non-disabled over likely to be alive & non-disabled over timetime

Increased treatment explains approx. Increased treatment explains approx. 50% of the disability decline50% of the disability decline

21% more elderly IHD patients 21% more elderly IHD patients would have been alive and non-would have been alive and non-disabled in 1999, if all lived in high disabled in 1999, if all lived in high treatment areas treatment areas

Improved care and outcomes Improved care and outcomes possible through increased use of possible through increased use of appropriate IHD treatmentsappropriate IHD treatments

FundingFunding

Funding:Funding: National Institute on Aging (P30 National Institute on Aging (P30

AG12810 and R01AG019805)AG12810 and R01AG019805) Mary Woodard Lasker Charitable Mary Woodard Lasker Charitable

Trust Trust Michael E. DeBakey Foundation Michael E. DeBakey Foundation

Results: Health Status at Results: Health Status at Follow-UpFollow-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

1984 1989 1994 Difference 1994-1984

p-value*

% Disabled 23.1 22.3 21.2 -1.9

0.004% Dead 37.7 34.0 31.0 -6.7

% Alive & Non-disabled

39.2 43.7 47.8 8.6

Area-Level Treatment Area-Level Treatment

Percent Invasive ProceduresPercent Invasive Procedures 1010thth percentile: 6% in 1984 and 18% by 1994 percentile: 6% in 1984 and 18% by 1994 9090thth percentile: 40% in 1984 and 70% by 1994 percentile: 40% in 1984 and 70% by 1994

Percentiles of Care:Percentiles of Care:

1010thth 9090thth

Beta Beta BlockersBlockers

34.734.7 68.7 68.7

Ace-Ace-InhibitorsInhibitors

46.7 46.7 74.0 74.0

AspirinAspirin 69.7 69.7 84.4 84.4

ReperfusionReperfusion 56.2 56.2 77.677.6

CCP MeasuresCCP Measures