Yearly flu shots are strongly recommended for adults with certain chronic illnesses, but patients of racial/ethnic minority groups are less likely to receive them. Perceived discrimination may be a contributing factor, but can't completely explain the racial/ethnic disparity, reports a study in Medical Care. The journal is published by Wolters Kluwer.

Patients who report discrimination in healthcare settings are about half as likely to receive seasonal influenza vaccine - but the difference becomes nonsignificant after adjustment for other factors, according to the study, led by Dr. Will Bleser, MSPH, of Penn State University and Muriel Jean-Jacques, MD, of Northwestern University Feinberg School of Medicine. They write, "The causes of persistent racial/ethnic disparities are complex and a single explanation is unlikely to be sufficient."

Discrimination Linked to, but Can't Explain, Lower Vaccination Rates

Annual seasonal influenza vaccination is strongly recommended for people at high risk of complications from influenza. That includes people with chronic diseases, such as asthma, heart or lung disease, or diabetes, as well as adults aged 65 or older.

To explore the reasons why minority patients are less likely to be vaccinated, the researchers analyzed survey responses from more than 8,000 white, black, or Hispanic Americans with chronic diseases. The survey was conducted as part of an independent evaluation of a national healthcare quality improvement project: the Aligning Forces for Quality (AF4Q) initiative, sponsored by the Robert Wood Johnson Foundation.

About seven percent of respondents perceived healthcare discrimination, based on the question: "Do you think there was ever a time when you would have gotten better medical care if you had belonged to a different race or ethnic group?"

Only 32 percent of subjects who perceived discrimination received the influenza vaccine, compared to 60 percent of those without perceived discrimination. Influenza vaccine uptake was lowest among black (that is, non-Hispanic black) respondents.

However, after adjustment for other determinants of health services, discrimination was no longer a significant factor. The adjusted analysis identified three factors associated with a higher probability of vaccination: having a college degree, not being a current smoker, and having greater trust in the information provided by one's doctor.

Despite intensive efforts, rates of recommended influenza vaccination remain below target levels, especially in high-risk groups such as chronically ill adults. There are also well-documented racial/ethnic disparities in uptake of flu vaccine, which persist after other patient characteristics are taken into account.

Why are minority patients less likely to be vaccinated? There may be many contributing factors, including disparities in healthcare access, greater distrust of physicians, and unconscious racial bias by healthcare providers. There's growing interest in understanding how perceived discrimination, especially in healthcare settings, may affect health outcomes.

The study shows that influenza vaccination rates are lower for black and Hispanic patients. When examined on its own, perceived discrimination accounts for 16 percent of the racial/ethnic disparity in receipt of the flu vaccine.

However, after adjusting for other factors, the contribution of perceived discrimination to the disparity is no longer significant. That may reflect the relatively low prevalence of perceived discrimination in this nationwide study. Larger studies might show a significant effect, the researchers suggest.

Meanwhile, the study links other factors to a higher likelihood of vaccination, including higher education, not smoking, and having a trusting relationship with doctors. Mr. Bleser, Dr. Jean-Jacques and their coauthors conclude: "Clearly the causes of influenza vaccination disparities are complex as they have remained for decades, and from this study, the role discrimination plays is not entirely clear."

Article: Racial/Ethnic Disparities in Influenza Vaccination of Chronically Ill US Adults: The Mediating Role of Perceived Discrimination in Health Care, Bleser, William K. MSPH; Miranda, Patricia Y. PhD, MPH; Jean-Jacques, Muriel MD, MAPP, Medical Care, doi: 10.1097/MLR.0000000000000544, published online 25 April 2016.