assessing carotid endarterectomy: phase 1
TRANSCRIPT
A Horse of a Different Color: Outcomes and Health Services
Research
Ethan A. Halm, MD, MPH
Professor of Internal Medicine and Clinical Sciences
Biomedical Research Spectrum
• Bench Research: Basic Science• Translational Research
– Bench to bedside• Clinical Research
– Bedside is the lab• Outcomes & Health Services
Research– Real world care in communities
and populations is the lab
What is Outcomes and Health Services Research?
• Evaluating the impact of health care on health outcomes of patients and populations
• Drugs, devices, procedures, clinical strategies, system interventions
• Focus on care delivered in real-world settings not ideal care in randomized controlled trials
• Assess impact of health care on a broad range of patient-oriented outcomes: mortality, morbidity, symptom burden, functional status, quality of life, satisfaction, utilization, costs
Traditional Medical Research Framework
Causal Factor(bacteria, gene)
Modifying FactorsPatient factorsEnvironmentHealth care
Outcome(disease)
Outcomes & Health Services Research Framework
Health Care(treatment)
Modifying FactorsPatient factorsEnvironment
Outcomes(survival)
Why Evaluate Health Services?• Too hard to figure out the cause of disease• Figuring out the “cause” of disease might not
necessarily cure it (CF, Sickle Cell Anemia)• Assess how well something works in real world
practice, for whom, in which settings• To see if what we do is worth the money• Identify ways to improve health and health care• Identify care that could be harmful: overuse, errors
Two Examples
• Lung cancer
• Stroke prevention surgery
Understanding Racial and Ethnic Differences in Lung Cancer Outcomes
• Lung cancer is common and deadly• 80% are non-small cell lung cancer • Early stage non-small cell lung cancer is
potentially curable with surgery• Blacks have worse lung cancer outcomes
than Whites– 5-year survival: 26% Blacks v. 34% Whites
• Are there also Hispanic v. White differences?– And if so, WHY???
Combining National Datasets to Evaluate Ethnic Differences in Cancer Outcomes
• National cancer registry (SEER)• Registry of newly diagnosed cancer cases• Representative of US population• Data on age, gender, race, ethnicity, cancer
stage, initial cancer treatment• Medicare insurance billing data (Age ≥ 65 yrs)
• More complete info on: other health problems, what care people got over time
• National Death Index: long term survival
National Cancer Registry (SEER)
Methods
Identified all cases of early stage lung cancer in SEER-Medicare database between 1991-2000
16,000 patients treated in real world practice
Compare rates of death due to lung cancer for White v. Hispanics several ways:
Unadjusted rates of death due to lung cancer Adjust for other things that alter life expectancy
(age, gender, other health problems) Adjust for most important factor—potentially
curative surgery
0 2 4 6 8 10
Years after Diagnosis
0
0.2
0.4
0.6
0.8
1.0P
ropo
rtio
n S
urvi
ving
1 3 5 7 9
0.1
0.3
0.5
0.7
0.9
Whites
Hispanics
P= 0.008
Whites Had Better 5 Year Survival Compared to Hispanics: 62% v. 54%
Wisnivesky J, McGinn T, Iannuzzi M, Halm E. AJRCCM 2005.
0
0.2
0.4
0.6
0.8
1.0
0 2 4 6 8 101 3 5 7 9
0.1
0.3
0.5
0.7
0.9
Years after Diagnosis
Pro
port
ion
Sur
vivi
ng
Whites, with surgery
Hispanics, with surgery
P= 0.12
Whites, without surgery
Hispanic , without surgery
P= 0.52
Ethnic Differences in Survival Were Due to Differences in Receiving Curative Surgery
Conclusions• Hispanics with early stage lung cancer had
worse survival as compared with Whites
• Disparities are due lower rates of surgery and higher rates of worse cancer stage
• Patient-level study interviewing patients and physicians to identify barriers to minorities getting the most effective cancer treatment
Carotid Endarterectomy (CEA) Made Ridiculously Simple
• 1 in 4 strokes due to carotid artery disease• CEA seeks to prevent stroke by removing carotid
artery plaque that can embolize, clot, or occlude• Internal carotid artery supplies the retinal, anterior
and middle cerebral artery • Carotid distribution strokes and TIAs manifest as
eye, hand, arm, or leg symptoms or language/speech difficulties
• Intermediate risk vascular procedure lasting 90 minutes (general or local anesthesia)
Who has Carotid Artery Disease?
• Patients with stroke, TIA• Other high risk patients
– Coronary artery disease– Peripheral vascular disease – HTN, DM, high cholesterol, smokers– Elderly patients
Major Clinical Indications
• Symptomatic: more to gain– Stroke – Carotid TIAs
• Asymptomatic: less to gain– Asymptomatic CEA alone– Asymptomatic combined with CABG– Vertebrobasilar TIAs
Early Use of Carotid Endarterectomy
• In the 1980s, carotid endarterectomy (CEA) was controversial
• Data on efficacy was lacking and complication rates were high
• RAND Medicare study of CEA in 1981:– 32% were for inappropriate indications– 75% were for symptomatic carotid stenosis
(Strokes and TIAs)
Clarifying the Benefits and Risks of Carotid Surgery: Clinical Trials• Randomized controlled trials done to see if
surgery is better than medical treatment , and determine which patients benefit
• Over 10,000 patients randomized in North American & Europe (incl. UT Southwestern) at cost of $100 million
• In ideal settings of carefully selected patients & surgeons surgery was better
• Rare investment in trials to evaluate medical or surgical procedures
Outcomes and Use of Carotid Surgery in Real World Practice
• Assess if investment in clinical trials improved rates of appropriateness of surgery– Does better evidence change practice?– Is there a return on investment in clinical trials?
• Measure surgical outcomes in real world practice (risk of death and stroke)– Do patients in real world care do as well?
• Examine the impact of other health problems on risk of surgical complications– Can you produce more personalized info for
individual decision making?
Did Evidence Influence the Use of Carotid Endarterectomy?
0
20
40
60
80
100
120
140
160
1980 1982 1984 1986 1988 1990 1992 1994 1996 1998 2000 2002
Nu
mb
er (
1000
's)
NASCET: SX
ACAS: ASX
New York Carotid Artery Surgery (NYCAS) Study
• Collaborative grant between NIH and national Medicare agency
• Used Medicare billing records to identify all CEAs in Medicare patients in NY State
• Research nurses reviewed hospital records and collected detailed clinical info about patients, surgery, outcomes within 30 days of CEA
• 9,588 patients, 166 hospitals, 488 surgeons
Defining Appropriateness: RAND Group Judgment Methodology• Multidisciplinary, national expert panel to rate,
discuss, and re-rate appropriateness of 1557 indications for CEA
• Indication is clinical scenario in which CEA might be considered
• Appropriateness rating for each clinical scenario:– Inappropriate: risks > benefits– Uncertain: benefits = risks– Appropriate: benefits > risks
Appropriateness of CEA in NYCAS: 1998-1999
0.87
87%Appropriate
4% Uncertain
9% Inappropriate
Does Evidence Change Practice? Appropriateness of
Surgery Improved
Appropriate Uncertain Inappropriate0
102030405060708090
100
35 32 32
87
49
RAND
NYCAS
Percent
P<.0001
Halm et al. Neurology 2007
Are Outcomes in Real World Practice as Good as the Trials? 30 Day Stroke/Death Rates (%)
Observed Benchmark
CEA Alone
Symptomatic 6.4 < 6
Asymptomatic 3.0 < 3
Carotid + Heart Surgery
Asymptomatic 11.1 ???
Conclusions• Since large investment in RCTs of CEA:• Good news: Triumph of evidence based medicine
– Inappropriateness (32% to 9%)– Complication rates in unselected practice similar to RCTs
• Not so good news:– 1 in 11 still inappropriate– Extrapolates to 12,000 unneeded CEAs/yr in US
• Bad news:– Shift from high benefit symptomatic Pts to lower benefit
asymptomatic Pts (25% to 72%)
Other Health Problems IncreaseRisk of Death/Stroke: Asymptomatic Pts
2.5%2.0%
4.0%
7.1%
0%
1%
2%
3%
4%
5%
6%
7%
8%
Death/stroke*
NoneLowModerateHigh
*p<.001
Comorbidity
Thinking Beyond the RCTs: Asymptomatic v. Symptomatic
3.0%
6.4%
0%
5%
10%
15%
Asymptomatic Symptomatic
Dea
th/S
tro
ke
Halm et al, Stroke, 2008
Risk of Complications after CEA and Neurological Acuity
2.7%4.1%
5.6%
7.9%
13.3%
0%
5%
10%
15%
ASX,No HxCVD
ASX,PastCVD
TIA CVA Acute
Dea
th/S
tro
ke
Halm et al, Stroke, 2008Symptomatic
Multivariable Risk Factors for 30-Day Death or Stroke
Risk Factor Odds Ratio DomainAge >80 yrs 1.3Non-White 1.8 SESASX: Distant Hx TIA/CVA 1.4TIA as indication for CEA 1.8 Neurologic
AcuityCVA as indication for CEA 2.4Acute syndrome 3.6Contralateral stenosis >50% 1.4 Disease severityDeep carotid plaque ulcer 2.1Admitted from ED 1.9Severe disability 2.9CAD 1.5 ComorbidityDM on insulin 1.6
Racial and Ethnic Disparities in Outcomes and Appropriateness of
Carotid Endarterectomy
Background: Disparities in Carotid Endarterectomy (CEA)
• Non-Whites have higher rates of stroke but are less likely to have CEA – NYCAS 5% were Black or Hispanic
• Prior studies showed inconsistent effects of race on outcomes of CEA
• Most focused solely on mortality, used claims data, or limited to Black v. White differences
Study Aims
• Measure differences in indications for CEA and perioperative risk in Blacks and Hispanics compared to Whites
• Compare the risk of death or stroke within 30 days of CEA in Blacks, Hispanics, and Whites
• Understand reasons for disparities in perioperative outcomes by adjusting for other risk factors that influence outcomes
Higher Rates of Symptomatic Indications for CEA in Non-Whites
73%
19%
8%
64%
19% 17%
67%
18%15%
0%10%20%30%40%50%60%70%80%
Asymptomatic TIA Stroke
White Black Hispanic
Halm, Stroke 2009 *p<.001
Higher Rates of Comorbidity and Perioperative Risk in Non-Whites
0%
10%
20%
30%
40%
50%
60%
70%
None/Low Moderate High
White Black Hispanic
Revised Cardiac Risk Index, *p<.0001
Higher Overall Rates of 30 Day Death/Stroke after CEA in Blacks
and Hispanics
6.9%
3.8%
9.5%
0%1%2%3%4%5%6%7%8%9%
10%11%12%13%14%15%
White Black Hispanic *p<.0001
Disparities in Perioperative Complications: Death, Stroke
2.7%2.2%
5.6%4.8%
3.1%
1.1%
3.0%
7.0%6.5%
0%1%2%3%4%5%6%7%8%9%
10%
Death* Any stroke** Non-fatalstroke**
WhiteBlackHispanic
*p<.05, **p<.005
Disparities in 30 Day Death/Stroke: Asymptomatic Patients (N=6503)
5.5%
2.8%
7.6%
0%1%2%3%4%5%6%7%8%9%
10%11%12%13%14%15%
White Black Hispanic *p<.001
3% benchmark
Disparities in 30 Day Death/Stroke: Symptomatic Patients (N=2590)
9.4%
6.3%
13.0%
0%1%2%3%4%5%6%7%8%9%
10%11%12%13%14%15%
White Black Hispanic *p<.05
6% benchmark
Reasons for Disparities in Death or Stroke: Multivariate Analyses
UnadjustedOR
AdjustedModel 1
Adjustment None Indication
White 1.0 1.0
Black 1.89* 1.75*
Hispanic 2.67* 2.54*
*P<.05
Reasons for Disparities in Death or Stroke: Multivariate Analyses
UnadjustedOR
AdjustedModel 1
AdjustedModel 2
Adjustment None Indication Pt factors
White 1.0 1.0 1.0
Black 1.89* 1.75* 1.51†
Hispanic 2.67* 2.54* 2.26*
*P<.05, † P=.13Patient factors: indication, age, sex, comorbidity, % stenosis, ED admission, deep ulcer, Rankin disability score
Reasons for Disparities in Death or Stroke: Multivariate Analyses
UnadjustedOR
AdjustedModel 1
AdjustedModel 2
AdjustedModel 3
Adjustment None Indication Pt factors Pt, MD,Hospital
White 1.0 1.0 1.0 1.0
Black 1.89* 1.75* 1.51† 1.37
Hispanic 2.67* 2.54* 2.26* 1.95*
*P<.05, † P=.13Patient factors: indication, age, sex, comorbidity, % stenosis, ED admission, deep ulcer, disabilityMD/Hospital factors: high and low volume
Inappropriateness by Race/Ethnicity
• Disparities in Inappropriateness: – Hispanics (16%), Black (12%), White (8%)*
• Disparities greatest for asymptomatic patients:– Hispanic (18%), Black (15%), White (8%)*
• Reasons for inappropriateness did not differ in the 3 groups
• More minority Pts presented with high comorbidity
• Among all Pts with high comorbidity, same % inappropriate across race/ethnic groups
*p<.001
Disparities: Worst of All Worlds
• CEA is underused among eligible Non-Whites• Among Non-Whites who have CEA, rates of
inappropriateness is higher (overuse)• Non-Whites have worse outcomes• Reasons for the disparities in outcomes were
multifactorial
Health Services Research Question:
Does Managed Care Affect Quality? Appropriateness, Referral Patterns and Outcomes of Carotid Endarterectomy
Rates of Appropriateness: Fee-For-Service to Managed Care
86.9
4.48.6
88.6
38.4
0102030405060708090
100
Appropriate Uncertain Inappropriate
Percent FFS
MC
P=.78Halm et al. Am J Med Quality 2008
No Difference in 30 Day Outcomes of CEA: FFS v. MC
0123456789
10
Death
Stroke
Non-fata
l stro
ke
Death
/Stro
ke MI
TIA
Co
mp
lica
tio
n R
ate
(%)
FFS
MC
P > .51 for all
Other Areas of CEA Research• MD/Hospital volume-outcome relationships
– How do high volume folks get better outcomes?• Subspecialty Differences• Long term outcomes of NYCAS cohort
– 5 and 10 year stroke and death rates– Subgroup differences in outcomes– RCTs: Age 67, few comorbidities– NYCAS: mean age 75, many comorbidities
• Web-based decision aid to improve decision making in asymptomatic carotid disease
“Oh, if only it were so simple”