In general, patients lacked medication for a substantial proportion of the six months. But black, Hispanic and Native American patients were less compliant than white and Asian patients -- with only enough medication to cover a little more than half of the time period. And people living in the Midwest were less compliant than residents of other regions.
Overall, fewer than one-third of all patients had enough medication to cover at least 80 percent of the study period.
Dr. Cristina Drenkard, an assistant professor at Emory School of Medicine in Atlanta, said this finding is "very concerning."
Low-income minorities with lupus are known to fare worse than their white counterparts, and the reasons are probably many, noted Drenkard, whose research focuses on lupus. But it's likely that lesser adherence to drug regimens is one reason, she said.
Drenkard and her colleagues recently published a small study looking at whether a "self-management" program could help low-income black women with lupus. And they found that women who attended workshops at a public clinic were feeling better and doing a better job of taking their medication and generally managing their disease.
"We think self-management support like this is important for people with SLE," Drenkard said.
Still, a program like that would be only one part of the solution, these experts added.
"We need more research to understand what the barriers are to drug adherence, from the patient point of view," Yazdany said.
Another study to be reported at the same meeting underscores the importance of sticking with prescriptions. Researchers found that among more than 1,700 lupus patients in 11 countries, those taking anti-malaria drugs were less likely to show damage to their kidneys, heart or other organs over six years.
Do lupus patients with private insurance do a better job of sticking with their medications? It's not clear, said Yazdany. With Medicaid, there are state databases to comb through, but there is no similar way to study lupus patients with private insurance on a national level.
For now, Yazdany said it's important for all lupus patients to bring any medication concerns to their doctor. If side effects are an issue, she said, your doctor may be able to adjust the dose or switch the medication.