Biologic disease-modifying antirheumatic drugs revolutionized the treatment of rheumatoid arthritis, or RA, when the first ones were introduced more than a decade ago. The drugs are associated with better control of RA, less joint damage and higher rates of remission, but a new study finds that African-Americans are less likely to use them.

The study, published in Arthritis Care & Research, analyzed the records of 5,385 adult RA patients in California, all of whom had been prescribed either a biologic or a standard disease-modifying antirheumatic drug, or DMARD. The biologics in the study included: etanercept, or Enbrel; adalimumab, or Humira; anakinra, or Kineret; and infliximab, or Remicade. The traditional DMARDs included: methotrexate, or Rheumatrex; lefluonomide or Arava; hydroxychloroquine, or Plaquenil; and sulfasalazine, or Azulfidine.

The researchers set out to discover whether race/ethnicity played a role in determining what type of DMARD a patient was prescribed. The verdict, according to the data, is it does. The results show that just over 15 percent of all patients were prescribed a biologic – but only 9 percent of African Americans were, compared to 16 percent of Caucasians and 20 percent of Hispanics. Looked at another way, the numbers show African-Americans were 53 percent less likely to receive a biologic DMARD than Caucasians, and Hispanic patients were 36 percent more likely to get one than Caucasians.

The study, considered “retrospective” because it looked at existing records, used data from California’s Medicaid system, known as Medi-Cal, between 1998 to 2005. 

“I was surprised by the magnitude of these differences,” says study author Aniket Kawatkar, PhD, a research scientist in the Department of Research and Evaluation at Kaiser Permanente Southern California. “The fact that African-Americans are at 53 percent lower odds suggests there may be an urgent need for interventions targeted to reduce barriers in the uptake of biologic DMARDs in this race group.”

The authors say the disparity in African-Americans’ use of biologics does not appear related to what might be considered the usual suspects – insurance coverage, socioeconomic status or even disease severity. Rather, it seems patient preference and physician trust may be key factors in determining who gets what type of drug.

In fact, a 2009 study, published in the journal Medical Care, found that in a surveyed group of RA patients, more than three times as many Caucasian patients than African-American patients preferred aggressive therapy for the disease.

Kenneth Saag, MD, a professor of medicine in the Division of Clinical Immunology and Rheumatology at the University of Alabama at Birmingham, says the findings of the new study are concerning. “In general, biologic DMARDs represent a … therapy for rheumatoid arthritis that is, for many, a step above what they’ve been receiving,” he says.

Dr. Saag says there may be various reasons for racial disparities in medical care. For example, he points out that African-Americans get fewer joint replacement surgeries than Caucasians. He says a possible reason is that “African-Americans know far fewer people who have had a joint replacement surgery done and therefore may have less perspective on it.”

Still, he says you can’t rule out the possibility of “residual racism” on the part of health care providers – from physicians to pharmacists – and you can’t rule out just poor communication.

Given the serious nature of RA, Dr. Kawatkar says it’s important to find out why some patients may be refusing or otherwise not getting what is considered optimal treatment. “Since rheumatoid arthritis does not have a cure and remission is contingent on early diagnosis and treatment, if certain race/ethnic groups are resistant to certain treatments, or if they delay starting treatment, these patient groups will be systematically associated with poorer outcomes,” he says.

The lower biologic use among African-Americans is particularly surprising, given that this group has the lowest median age in the study, 53 years old. In a separate analysis, the study authors found younger patients far more likely to use a biologic than older patients. In fact, for those 45 and younger, the odds of getting a prescription for a biologic DMARD was more than twice that of those 65 and older.

Whatever the reasons for the disparity in biologic DMARD use, the study author suggests it could get worse. “Due to the disproportionate increase in Medicaid patients expected over the next few years as a result of the Affordable Care Act – and also due to the aging of baby boomers – new RA patients will be identified,” says Dr. Kawatkar. “Caregivers and policy makers need to be aware of such potential disparities in effective treatment, and patient education and outreach strategies need to be developed.”