The survey also reveals that some people who forgo the shot are skeptical about its effects.
Harvard University researchers say blacks in Medicare are about 40 percent to 45 percent less likely to report receiving a flu shot than whites with similar coverage, regardless of whether they're in an HMO or a fee-for-service plan.The researchers say they're not sure what's behind the dramatic gap, but it doesn't appear to be entirely the result of racial differences in attitudes about preventive care. The findings appear in the Sept. 26 issue of The Journal of the American Medical Association.
The study, led by Dr. Eric Schneider of the Harvard School of Public Health, looked at survey data from 13,700 people covered in 1996 under Medicare, the government's health insurance plan for people 65 or older. Of those, 8 percent were black.
The overall immunization rate among beneficiaries was about 66 percent, including 71.2 percent for people enrolled in managed care plans and 65.4 percent for those receiving fee-for-service care.
Blacks were far less likely in general to be vaccinated against the virus, the researchers say: 46 percent vs. 67 percent, a difference of more than 45 percent. And while the odds of vaccination improved for blacks in managed care, with about 51 percent receiving the shot, the disparity was the same. In neither payment plan did black beneficiaries approach the government's year-2000 goal of 60 percent flu immunization coverage.
Roughly one in five people who didn't get a flu shot said they thought it could cause the disease, while 15 percent said they believed it could trigger adverse reactions. Many said they were skeptical that the vaccine could prevent the virus, and nearly 13 percent said they "did not think about [the shot] or missed it" when it was offered.
The study found blacks and whites equally hesitant about vaccination, but the researchers weren't able to determine if that skepticism contributed to the disparate immunization rate.
"We don't know whether some of this difference might relate to whether patients trust what's in the vaccine, or if they feel it's helpful to them," says Schneider. African-Americans tend to be warier of the health-care system in general, he says.
The researchers were unable to study another potentially important factor -- whether vaccine services are scarcer in predominately black communities than they are in mostly white neighborhoods. Since there's only a four-month window for effective flu vaccination, if get-out-the-shot efforts aren't equally common "that might account for a big part of the difference," Schneider says.
Susan Pisano, a spokeswoman for the American Association of Health Plans, says racial disparities in health-care delivery are a concern and need further study. However, Pisano says the latest study reinforces the benefits of managed-care plans when it comes to immunization.
"It's something that the plans work at. They have adult immunization programs and projects, and some send reminders" to members about the importance of vaccination. Pisano says another encouraging finding is that black managed-care members are significantly more likely to report having seen a doctor recently than those with fee-for-service insurance.
Immunization is far from the only health area in which racial disparities are common. Studies have turned up gaps in treatment and access to care between whites and minorities, particularly blacks and Hispanics, in use of cardiovascular drugs and procedures, hip and knee replacements and kidney transplants.
The origins of the disparities and different preferences for treatment among ethnic groups are difficult to divine, writes Dr. Jeffrey Katz of Brigham and Women's Hospital, in Boston, in an editorial accompanying the journal article. "Certainly one possibility is the lingering effects of racial and sex discrimination."
The "paucity of minority physicians may influence preferences for care," Katz writes.
Whatever the case, Katz says physicians must take pains to learn their patients' treatment preferences, whether their fears and concerns are accurate, and try to promote sound choices in a "non-threatening, culturally sensitive manner."
What To Do
The Medical College of Wisconsin reviews known racial disparities in health care.
For more on the government's health insurance system, visit the Health Care Financing Administration, which administers the programs.
Try the Centers for Disease Control and Prevention to learn more about the flu and flu vaccination.