Urban/Rural Differences in Survival Among Medicare Beneficiaries with Breast Cancer

1. Urban/Rural Differences in Survival Among Medicare Beneficiaries with Breast Cancer Melony E.S. Sorbero, Ph.D. RAND Corporation Funded by Health Resources and Services Administration Office of Rural Health Policy

2. Lisa R. Shugarman, Ph.D. Haijun Tian, Ph.D. Arvind Jain, M.S. J. Scott Ashwood, M.A.

3. Background – Breast Cancer • High incidence of breast cancer • Most common cancer type in women • Probability of diagnosis increases with age • Second leading cause of cancer death in women • American Cancer Society estimates for 2007 • 178,480 women will be diagnosed with invasive breast cancer • 40,460 will die

4. Background – Rural Health • Rural areas are characterized by: • Lower population density • Large distances between individuals and communities • Large distances from urban centers • Experience challenges recruiting and retaining providers • Hospitals and other facilities not capable of providing all services • Populations in rural areas travel further and wait longer for outpatient care • Rural elders more likely to be poor and near poor than urban elders

5. Objectives • To examine urban/rural differences in survival among women age 65 and older who have been diagnosed with breast cancer • Survival differences may exist due to • Urban/rural socioeconomic differences • Lower local supply of cancer services and providers in rural areas

6. Methods - Data • Three data sources • Surveillance, Epidemiology, and End Result (SEER) Data (1995-1999) • 14 cancer registries representing 26% US population • Linked Medicare administrative data (claims and enrollment database) (1994-2003) • Area Resource File (selected years for supply variables)

7. Methods - Sample • Inclusion criteria • Breast cancer was the first diagnosed cancer • Female • Continuously enrolled in both Medicare Part A & B for 1-year before diagnosis through 8 months after diagnosis • Exclusion criteria • Enrolled in managed care (N=12,843) • Eligible for Medicare for ESRD diagnosis or disability (N=16,326) • Breast cancer diagnosed via autopsy or death certificate (N=47) • N=32,626

8. Methods – Defining Urban/Rural • County-based definitions create a single label for counties with hetergeneous population densities • 1990 Rural-Urban Commuting Area (RUCA) Codes • Based on Census Bureau’s definitions of urbanized areas and urban places (population density and commuting patterns) • Acknowledges great variation across rural areas • Developed based on census tract and cross-walked to zip code • Four categories created: Urban, Large Rural, Small Rural, and Isolated Rural communities

9. Methods – Survival Analysis • Cox proportional hazard models • Hi(t) = • Parametric tests of proportional hazards assumption • Overall survival time in months • Date of diagnosis (mid-point of month) to date of death • Survivors censored at end of study period

10. Methods – Survival Analysis • Variables entered into model in stages • RUCA codes and demographic variables • Age, gender, race, marital status, number of comorbidities • Breast cancer variables • Year of diagnosis, stage, ER and PR status • Sociodemographic and supply variables • 15% + of population not speaking English well, median household income, and Medicaid status • HPSA Residence, number of radiation oncologists and number of hospital oncology services per 10,000 population 65+

11. Results – Sample Characteristics ** p<0.01; * p<0.05

12. Results – Sample Characteristics ** p<0.01; * p<0.05

13. Results – Sample Characteristics ** p<0.01; * p<0.05

14. Multivariate Results **** p<.0001; *** p<.001; ** p<.01

15. Multivariate Results - Supply **** p<.0001; *** p<.001; ** p<.01; * p<.05

16. Summary • Rural residence defined by RUCA categories not consistently associated with mortality following a breast cancer diagnosis • Controlling for demographics, higher mortality in large rural and small rural categories • Residing in county with partial or whole HPSA designation associated with increased mortality, while increased supply of hospital-based oncology services associated with decreased mortality

17. Limitations • Measures of supply based on county not RUCA codes • Hospital-based oncology services a proxy for all such providers • Did not examine disease-free survival • Findings may not be generalizable to Medicare beneficiaries enrolled in managed care or non-elderly

18. Conclusions • Women with breast cancer in rural areas experience greater mortality • Individual and regional socioeconomic factors associated with risk of mortality • Some evidence provider supply associated with mortality in elderly breast cancer patients • Policies should be developed to address provider shortages in both rural and urban areas