Apparent Widening Gap in Access to Neuro-oncologic Care in the United States: Title and subTitle BreakNeed for ActionWidening Gap in Access to Neuro-oncologic Care

Following the devastation caused by Hurricane Katrina in New Orleans in 2005, the United States has aggressively pursued a national effort to eliminate disparities in health care access. That tragic event uncovered the silent and hidden epidemic of health disparities that has persisted in this nation and threatened the lives of ethnic minorities and the poor. In particular, studies by the Centers for Disease Control and Prevention showed that the population was experiencing chronic untreated medical problems such as hypertension, diabetes mellitus, cardiovascular diseases, and psychiatric disorders. In some cases, evacuees received medical treatment for the first time for life-threatening diseases.^{1 - 3} Created by Congress in 2000, the National Center on Minority Health and Health Disparities had already begun implementing programs to promote research and intervention in minority health care. Since 2005, the center has received more than $990 million for minority health care research and initiatives. The requested budget for 2010 of $208 844 000 will put the amount spent on this critical issue over $1.3 trillion (http://ncmhd.nih.gov). After so many dollars spent, what advances have we made and what have we learned to move to more egalitarian health care?

The work of Mukherjee et al^{4 - 5} is timely and important because it examines disparities in the delivery of neurosurgical and neuro-oncologic care to minorities and the poor of this nation. The authors identified a large population of adult patients with the use of the Nationwide Inpatient Sample database. They then linked individual patients to the Area Resource File database by using the Federal Information Processing Standards Code, which corresponds to each specific hospital and county. They conclude that access to high-quality neuro-oncologic care has actually worsened for African American and Hispanic populations during the past 10 years. They also note that access worsened for older individuals. The authors point out, not surprisingly, that residents of counties with higher median household income and greater neurosurgeon density are more likely to have access to high-quality neuro-oncologic care.

Reviewing the methods of this study⁴ reveals a few areas of concern. First, while attempting to analyze a specific cohort of patients (those with brain tumors), the authors' inclusion criteria allowed for a much more heterogeneous population than desired. For example, among the procedure codes used for inclusion were codes for elevation of skull fracture fragments, implantation and removal of neurostimulation devices, and placement of skull tongs or halo traction. Although these codes represent neurosurgical procedures, they are not likely to apply to patients with brain tumors. Thus, the denominator of patients studied was unnecessarily diluted. Furthermore, the inclusion criteria stated that patients with “ ICD-9 diagnosis codes of brain tumor or ICD-9 procedure codes consistent with craniotomy for tumor biopsy or resection”^{4 (p248)} were included. By not linking the diagnosis and procedure codes, the data set may have included patients with brain tumor admitted for purposes other than surgical treatment of their tumor. Furthermore, the study did not address transfers to high-volume hospitals and ways to track these transfers. These limitations raise concerns about the conclusion that African Americans and Hispanics have worse access to high-quality neuro-oncologic surgical care. Nevertheless, the data suggest that, across a variety of admission types, this population is less likely to be admitted to high-volume neurosurgical centers. Furthermore, the trend over time of fewer admissions to high-volume centers remains significant and alarming.

Studies have demonstrated that high-volume providers have superior outcomes after surgical resection of malignant intracranial tumors.⁶ Outcome is also positively correlated with physician volume for stroke care,⁷ carotid artery stenting,^{8 - 9} pediatric transplant surgery,¹⁰ and aneurysm repair.¹¹ Given that high-volume providers may offer better outcomes, it is crucial for equity of care that minority patients have access to high-volume hospitals. However, disparities in minority access to care at high-volume hospitals have been observed in several surgical and medical disciplines. In particular, Bao and Kamble¹² studied differences in using high-volume hospitals and surgeons for coronary artery bypass graft across 19 hospital referral regions in Florida. The study reports a correlation between countywide surgeon density and access to care. The results indicate that minorities were significantly less likely than whites to receive coronary artery bypass grafts at a high-volume hospital. However, controlling for differences between regions eliminated almost all racial/ethnic differences. Substantial differences in using high-volume providers existed between Medicaid/uninsured and privately insured patients, and such differences persisted within hospital referral regions.

The study by Mukherjee et al⁴ likewise notes a correlation to countywide neurosurgeon density and access to care. This suggests that geographic distance to high-volume hospitals may be an important barrier to access. However, recent studies^{13 - 14} evaluating racial and ethnic differences in the use of high-volume hospitals in the New York City area for surgical procedures also found that minority patients are less likely to use high-volume hospitals and surgeons for procedures for cancer surgery (breast, colorectal, gastric, lung, or pancreatic resection), cardiovascular disease (coronary artery bypass graft, coronary angioplasty, abdominal aortic aneurysm repair, or carotid endarterectomy), or orthopedic conditions (total hip replacement). These findings support the idea that geographic proximity to a high-volume center is not the only determinant of access to care.

The National Center on Minority Health and Health Disparities has recognized that nonbiological factors affect health care, specifically social, behavioral, and environmental influences. To address disparities in health care access, we must identify the barriers to access on the side of the patient and on the side of the health system. Chang et al¹⁵ studied referral to high-volume hospitals for pancreatic cancer resection and found that patients older than 85 years, African Americans, Hispanics, and Asians were significantly less likely to be referred relative to their younger white counterparts.

The US government has recognized the importance of addressing disparities in health care for minorities, as evidenced by the funds committed to research and intervention. The research should focus on understanding the barriers and establishing standards of patient referrals, and attention should be given to the evaluation of systems of collaboration between low- and high-volume hospitals. Mukherjee and colleagues should be commended for identifying the disturbing trend of worsened access to high-volume care among minority and elderly patients. To reverse this trend and to offer equal access to the same resources of neuro-oncologic care for all, we must understand and fix the barriers and take the message to primary care physicians, minority patients, and the elderly.

Correspondence: Dr Riley, Division of Neurosurgery, Department of Surgery, The University of Alabama at Birmingham, Faculty Office Tower 1050, 150 Third Ave S, Birmingham, AL 35295.

Author Contributions:Study concept and design: Riley and Fathallah-Shaykh. Acquisition of data: Riley. Analysis and interpretation of data: Riley. Drafting of the manuscript: Riley and Fathallah-Shaykh. Critical revision of the manuscript for important intellectual content: Riley and Fathallah-Shaykh. Administrative, technical, and material support: Riley. Study supervision: Riley and Fathallah-Shaykh.

Financial Disclosure: None reported.