Increased Breast Cancer Survival Differentials by Race in America

1
Increased Breast Cancer Survival Differentials by
Race in America

• Historic Observational Evidence Consistent With a
  Health Insurance Hypothesis, 1975 to 2000

2
Research Objective

• To learn from our experiences of the past
  generation whether or not health care outcomes
  (resources) have become more or less equitably
  distributed
• - African American vs. white people
• - In metropolitan Detroit
• - With breast cancer (sentinel outcome)

3
Historical Context 1975 to 2000

• - US health care system is multi-tiered
  Uninsured, underinsured, Medicaid, Medicare, and
  array of private coverages
• - Time of great systemic changes
• - Managed care for-profit proliferation
• - Uninsured population nearly doubled
  (increased from 24 to 44 million among those lt
  65 years of age)

4
Theoretical Context Systematic Literature Review

• - Race and socioeconomic status (SES) are
  strongly associated with health insurance
  statuses (ORs 2.0 to 15.0).
• - Race, SES and health insurance statuses are all
  strongly associated with cancer screens, stages
  at diagnosis and access to treatments (ORs 2.0 to
  5.0).

5
Research Questions

• Given the near 20 improvement in breast cancer
  survival during the study period
• 1. Has this medical advance been enjoyed
  equitably by African American and white women?
• 2. Is there a particular African American
  disadvantage among those not yet eligible for
  Medicare?

6
Methods

• Using Historical Cohorts and Focusing on
  Interactions, Rather Than Mere Main Effects

7
Sample Design

• - Detroit Cancer Registry, SEER
• - Detroit metro 3 counties, 4 million pop
• - Primary invasive breast cancer cases
• - Women, 25 years of age and older
• - Entire most valid cohort
• 1975 to 2000 inclusive followed until December
  31, 2001
• - N 57,668
• 10,237 African American and
• 47,431 White people

8
Analytic Plan

• - 1970s 1990s cohorts compared, e.g.,
• 1975-80 followed until 1986 vs. 1990-95 until
  2001 for 5-year survival analyses
• - Analyses of survival used proportional hazards
  models.
• - Analyses of stages of disease at the time of
  diagnosis and treatments (1st year
  post-diagnosis) used logistic regression models.
• - All models were adjusted for age and year of
  diagnosis.

9
Results

• Significantly Increased Racial Group Breast
  Cancer Survival, Stage and Treatment Differentials

10
Race By Cohort Interactionsa on Survival Odds
Ratios (95 CIs)Main Effects of Race Within
Cohort 1970s 1990s

• 1-yr 1.83 (1.60,2.09) 2.07 (1.86,2.31)
• 3-yr 1.67 (1.51,1.86) 2.09 (1.93,2.26)
• 5-yr 1.64 (1.46,1.84) 1.94 (1.79,2.16)
• 10-yr 1.64 (1.40,1.91) 1.88 (1.66,2.13)
• a All minimally significant at p lt .05).

11
Race By Age By Cohort Interaction on 5-Year
Survival ORs (95 CIs) Race By
Age Within Cohort Age 1970s 1990s

• lt 65 1.60 (1.39,1.84) 2.06 (1.85,2.30)
• 65 1.74 (1.41,2.16) 1.79 (1.58,2.04)
• The 3-way interaction was significant at p lt
  .05).

12
Race By Age By Cohort Interaction on Local
Disease ORs (95 CIs) Race By Age
Within Cohort Age 1970s 1990s

• lt 65 1.24 (1.12,1.37) 1.46 (1.35,1.58)
• 65 1.58 (1.36,1.84) 1.56 (1.41,1.72)
• The 3-way interaction was significant at p lt .05).

13
Race By Age By Cohort Interactions on Treatments

• Similar interactions were observed on receipt
  of surgery (localized disease), radiation
  therapy (local regional), chemotherapy and
  hormone therapy (regional disease).
• All were indicative of particularly increased
  African American disadvantages among those not
  yet eligible for Medicare.

14
Interactions Seem to Reflect Sociologic, Not
Biologic Phenomena

• When four socioeconomic variables were entered
  into the analytic models each of the previously
  significant interaction terms did not enter
• (at p lt .05).
• The four measures were census tract- based
  compositional (prevalence of poor and near poor
  200 poverty criterion people) and contextual
  (median home and rental values) measures of
  social position.

15
Discussion
The Evidence Supports Race as a Social
Construction The Implementation of Policies
That Would Ensure All Americans Access to
Timely Diagnosis the Best Available Treatments

16
Summary

• African American women with breast cancer have
  not fully enjoyed contemporary survival advances.
  Relative to white patients they are more
  disadvantaged today than they were 25 years ago.
• Alternative Explanations
• - Social policies and structures affecting health
  insurance access have changed drastically during
  this time frame.
• - Gene-based, biologically-mediated (tumor)
  characteristics have not.

17
Policy Implications

• - Race and income (type of insurance one has)
  still matter very much in American health care.
• - Racial and socioeconomic inequities could
  probably be eliminated in large measure by
  providing universal access to all
• - The young and the old
• - The poor and the rich
• - People of color and white people.