Uninsured patients who undergo surgery to remove a brain tumor could be twice as likely to die in the hospital as those who have the same operation but are privately insured, new Johns Hopkins research suggests. In teaching hospitals, where most neurosurgical procedures take place, those with government-subsidized insurance in the form of Medicaid were found in the same study to have rates of survival closer to those who are privately insured.

"Although the absolute rate of death in both groups is relatively low, the numbers are telling us that there's a disproportionate amount of mortality associated with not having any insurance at all," says Alfredo Quinones-Hinojosa, M.D., a professor of neurosurgery and oncology at the Johns Hopkins University School of Medicine and leader of the study described in the November issue of the Archives of Surgery. "We have a finding that patients with no insurance whatsoever have worse outcomes, and we don't have a medical explanation for why that is."

Quinones-Hinojosa emphasized that the disparities uncovered in a review of more than 28,000 patient medical records were unlikely to be accounted for by a patient's overall state of health, or the ability to access care, factors often cited to explain why the uninsured fare worse. In fact, the researchers found that in patients with no illnesses other than the brain tumor, the uninsured had a threefold higher risk of dying in the hospital compared to privately insured patients.

He says he was surprised to find that patients with state-supported insurance in the form of Medicaid did somewhat better than those with no insurance.

Approximately 612,000 people in the United States have a diagnosis of a primary brain or nervous system tumor. Malignant brain tumors cause roughly 13,000 deaths annually and those diagnosed have a five-year survival rate of about 35 percent.

In their study, Quinones-Hinojosa and his team analyzed data from 28,582 patients between the ages of 18 and 65 who underwent craniotomy (open-skull surgery) for a brain tumor between 1999 and 2008. The data were part of the Nationwide Inpatient Sample (NIS) database. Most of the patients with government insurance were on Medicaid and not Medicare because they were under the age of 65, when Medicare typically kicks in. The researchers found that the uninsured patients were twice as likely to die in the hospital as those who had the same operation but were privately insured.

In general, according to previous research, insurance status may influence health outcomes by affecting a patient's overall health, the ability to access care (meaning they come to a doctor after a disease has become more serious) or the quality of the treatment delivered. Quinones-Hinojosa says the study did not eliminate the possibility that patients who are not able to see a doctor regularly have some medical conditions that are undiagnosed, and therefore are not listed as having other medical conditions in the database that was used. These patients may appear healthy "on paper," but in reality, they could have any number of debilitating medical conditions and may be more likely to have a worse outcome after surgery.

Another possibility -- that caregivers treat uninsured patients differently -- is one that needs to be closely looked at, he says.

"This research raises more questions than it answers," he says. "Do we treat these patients differently because they don't have insurance? Are we more eager to withdraw care because the expense of caring for these patients falls on the shoulders of the hospital? I'm hoping that's not the case, but it's something we have to talk about. We need to be aware of these issues and make sure we are making decisions based on sound medical judgment and not some other factor."

Other research has been done and has found that for other critically ill patients, patients without insurance are more likely to die than those with private insurance.

The research was funded by grants made to the authors by the Doris Duke Charitable Foundation, VSBfonds, the Prins Bernhard Cultuurfonds and the Robert Wood Johnson Foundation.

Other Johns Hopkins researchers involved in the study include Eric N. Momin, B.A.; Hadie Adams, M.D.; Russell T. Shinohara, M.Sc.; Constantine Frangakis, Ph.D.; and Henry Brem, M.D.