Racial and Ethnic Differences in the Quality of Care for Patients Hospitalized with Myocardial Infar

1
Racial and Ethnic Differences in the Quality of
Care for Patients Hospitalized with Myocardial
Infarction, 1999-2002.

• Elizabeth H. Bradley, PhD
• Yale School of Public Health

2
Acknowledgements

• This work is funded by
• -National Heart, Lung, and Blood Institute
  (R01HS10407-01)
• -Patrick Catherine Weldon Donaghue Medical
  Research Foundation (02-102)
• -Claude D. Pepper Older Americans Independence
  Center at Yale (P30AG21342)

3
Collaborators

• Jeph Herrin, PhD
• Yongfei Wang, MS
• Robert McNamara, MD
• Tashonna Webster, MPH
• David Magid, MD
• Martha Blaney, PharmD
• Eric Peterson, MD
• John Canto, PhD
• Charles Pollack, MD
• Harlan Krumholz, MD

4
Background

• Many studies demonstrate different patterns of
  cardiovascular care by racial and ethnic groups
  (e.g., referral for cardiac catheterization, use
  of invasive tests)
• Few have investigated the relative contributions
  of socio-demographic, economic, clinical, and
  health system features to this racial/ethnic
  disparities

5
Why is this important?

• Elimination of racial/ethnic disparities in care
  is a national priority (IOM, CDC, AHRQ)
• To address disparities, we have to know their
  source and causal mechanisms

6
Research objectives

• We sought to
• Characterize racial/ethnic differences in quality
  of cardiovascular care for patients hospitalized
  with acute myocardial infarction (AMI)
• Examine factors that mediate or explain observed
  racial/ethnic differences in quality of care

7
Measuring quality of care for AMI

• Which quality indicator to use?
• - Evidence based
• - Well established in clinical guidelines
• - Substantial variation in country
• - Involving hospital systems

8
Time is muscle!

• Quality indicator endorsed by American Heart
  Assoc is time to acute reperfusion
• - 30 minutes door to drug (lytics)
• - 90 minutes door to balloon (PCI)

9
Study design and sample

• Retrospective, observational study using patient
  data from the National Registry of Myocardial
  Infarction, 1999-2002
• - fibrinolytic cohort n73,032 1,052 hospitals
• - PCI cohort n37,143 434 hospitals
• American Hospital Association Annual Survey of
  Hospitals, 2000.

10
Measurement outcome

• Door-to-drug time door-to-balloon time as
  continuous measures
• Log transformed for performing parametric
  analyses, in order to account for the skewness of
  its distribution
• Summary measures thus reported as geometric
  (i.e., logarithmic) mean

11
Measurement race/ethnicity

• Recorded by admissions clerk or nurse a set of
  dummy variables
• White
• African American/Black
• Hispanic
• Asian/Pacific Islander
• American Indian/Alaska native
• Other/Unknown

12
Statistical analysis

• We examined overall geometric means for door to
  treatment times for each racial/ethnic group,
  i.e., crude differences
• To explore how crude differences might be
  mediated by other factors, we employed
  multivariate, hierarchical models (built in
  sequence of steps)

13
Results

• Crude rates (mins) DTD DTB
• TARGET 30 mins 90 mins
• White 33.8 103.4
• Afr Am 41.1 122.3
• Hispanic 36.1 114.8
• Asian 37.4 105.8
• Am Ind 36.4 101.2
• Other 33.9 101.2
• P-value lt 0.01

14
Door to balloon times AfricanAmerican
(differences from white)

• Race/ethnicity effects Compared to white
• Overall crude 18.9 minutes
• Hosp cluster effects 12.6 minutes
• Age, sex, ins 12.9 minutes
• Clinical char 11.1 minutes
• Full model 8.6 minutes

15
Door to balloon times AfricanAmerican
(differences from white)

• Of the 18.9 minute crude difference,
• - 33.3 (18.9 -12.6/18.9) accounted for by
  hospital-specific effect
• - 21.2 (12.6 - 8.6/18.9) accounted for by
  patient-level factors and hospital
  characteristics
• - 45.5 (8.6/18.9) independently related to
  race/ethnicity

16
Door to balloon times Hispanic (differences from
white)

• Race/ethnicity effects Compared to white
• Overall crude 11.4 minutes
• Hosp cluster effects 3.2 minutes
• Age, sex, ins 4.9 minutes
• Clinical char 4.4 minutes
• Full model 3.7 minutes

17
Door to balloon times Hispanic (differences
from white)

• Of the 11.4 minute crude difference,
• - 71.9 (11.4 - 3.2/11.4) accounted for by
  hospital-specific effect
• - some negative confounding by sex, age
• - 32.5 (3.7/11.4) independently related to
  race/ethnicity

18
Discussion

• Marked differences in time to reperfusion by
  racial/ethnic group
• Especially apparent for African Americans, whose
  door-to-drug and door-to-balloon times are 20
  longer than for patients identified as white

19
Discussion

• Is the racial/ethnic disparity a result of
• - differential treatment inside the hospital
• - selection to different types of hospitals?

20
Discussion

• We found that a substantial portion of the
  differences in time to acute reperfusion time was
  explained by accounting for the hospital to which
  patients were admitted, especially for Hispanic
  individuals (70 of the door-to-balloon time
  disparity) but also for African American patients
  (30 of the disparity)

21
Implications

• Efforts to raise awareness of racial/ethnic
  disparities are important however
• These data suggest need for parallel efforts
  directed at improving the care at hospitals where
  minority groups receive care
• A systemic approach will be needed