N. R. Changoor1,2, J. W. Scott1, G. Ortega2, C. K. Zogg1, L. L. Wolf1, G. Reznor1, E. B. Schneider1, E. E. Cornwell2, A. H. Haider1 1Brigham And Women’s Hospital,Center For Surgery And Public Health,Boston, MA, USA 2Howard University College Of Medicine,Department Of Surgery,Washington, DC, USA
Introduction:
Studies have demonstrated that high volume centers are associated with superior outcomes for multiple cardiac, vascular and oncologic procedures. Racial/ethnic minority patients receive fewer of these procedures at high volume centers, the cause for which remains undetermined. Our study aims to investigate whether disparities in access to high volume hospitals are also associated with patient income.
Methods:
The 2005-2011 NIS was queried for patients with ICD-9-CM procedure/diagnostic codes for oncologic resection of the breast (BrCa), lung (LungCa), esophagus (EsophCa), stomach (GastCa) or colon (ColonCa) as well as for patients who underwent (procedure codes) CABG, AAA repair (AAAR), CEA, total hip replacement (THA), or total knee replacement (TKA). Hospitals treating patients within each operative group were dichotomized into centers that performed greater than 75th percentile (high volume centers) or less than the 25th percentile (low volume centers) of corresponding annual procedures. Median household income for patient's ZIP code was used to stratify patients into income quartile groups. Differences between the highest and lowest income quartiles were used to assess for associated differences in the risk-adjusted odds of presenting to a high-volume center for a given operation. Nationally-weighted, multivariable logistic regression accounted for differences in patient/hospital-level factors and clustering of patients within hospitals.
Results:
A combined total of 2,529,352 patients underwent included operations; most received surgery for BrCa (29.9%), TKA (21.3%) and THA (12.4%). The procedures with the highest proportion of high-income patients presenting to high-volume centers were ColonCa (90.6%), LungCa (74.7%), and BrCa (73.7%), while the procedures with the highest proportion of low-income patients presenting to high-volume centers included CABG (54.5%), AAAR (53.6%) and CEA (53.6%). Risk-adjusted analysis revealed that highest income patients were more likely to receive care at high-volume centers for THA (OR=1.96, CI:1.36-2.82), BrCa (OR=1.69, CI:1.07-2.67) and GastCa (OR=2.28, CI:1.05-4.94) but were less likely to receive care at high-volume centers for AAAR (OR=0.62, CI:0.40-0.95) when compared to lowest income patients. Differences for other procedures were not significant.
Conclusion:
The results indicate significant differences in access to high-volume centers associated with income for certain procedures. Varied associations demonstrated might imply important differences in respective patients’ ability and desire to receive care from high-volume centers, which may be dependent on the procedure type. Strengthening referral systems and re-evaluation of in-network referrals may help to increase access to high volume centers by low-income patients.