A federal prescription-subsidy program for low-income women on Medicare significantly improved their adherence to hormone therapy to prevent the recurrence of breast cancer after surgery.
"Our findings suggest that out-of-pocket costs are a significant barrier" to women complying with hormone therapy, said Dr. Alana Biggers, assistant professor of clinical medicine at the University of Illinois at Chicago College of Medicine, and lead investigator on the study. Programs that lower these costs can "improve adherence -- and, hopefully, breast cancer outcomes -- for low-income women," she said. Biggers presented the results of the study at an Oct. 14 press conference in advance of the American Society for Clinical Oncology Quality Care Symposium in Boston.
Breast cancer is a leading cause of cancer-related deaths for women of all races, but survival rates differ by race and socioeconomic status, with African American women and women of low income having higher rates of death.
Hormone therapy, such as tamoxifen or drugs called aromatase inhibitors, is usually taken for five years following mastectomy or surgery to remove breast tumors and can significantly reduce the risk that that cancer will return. Poor adherence to post-surgical hormone therapy regimens is associated with diminished chance of survival.
Biggers and her colleagues looked at data from the U.S. Centers for Medicare and Medicaid Services on adherence to hormone therapy for three years after breast cancer surgery. The 23,299 women, all 65 or older and enrolled in Medicare, were 86 percent white, 7 percent African American, 4 percent Hispanic, and 2 percent other racial backgrounds. All had had either a mastectomy or lumpectomy in 2006 or 2007.
Twenty-seven percent were enrolled in the Medicare Part D low-income subsidy, also known as the Extra Help program, which helps qualifying individuals pay for prescriptions. For the purposes of the study, medication adherence was defined as refilling a prescription as instructed 80 percent of the time or better.
"When we looked at women not enrolled in the subsidy plan, we saw that African American and Hispanic women had lower rates of adherence than white women," Biggers said. "But when we added in data from women enrolled in the subsidy plan, these disparities disappeared, and we saw that adherence rates improved and evened out across races."
The average rate of adherence over three years for women enrolled in the Extra Help program was 68 percent, compared to 52 percent for women not in the program. Sixty-one percent of women overall remained adherent to their hormone therapy over three years, with African American and Hispanic women having higher adherence rates -- 62 percent and 64 percent, respectively -- than white women at 58 percent. Biggers attributes this to the higher enrollment in subsidy programs among African American women (70 percent) and Hispanics (57 percent) compared to white women (21 percent) or women from other racial backgrounds (60 percent).
The data also showed that women enrolled in the Extra Help program have similar rates of adherence year after year, while adherence dropped over three years among women not in the program.
"Although we didn't study the effects of the Extra Help program on survival rates, any time you can improve adherence to a proven drug therapy, health outcomes are likely to improve," Biggers said.
Co-investigators on the research, all from the Medical College of Wisconsin in Madison, are Dr. John Charlson, assistant professor of medicine; Liliana Pezzin, professor of medicine in the Center for Patient Care and Outcomes Research; Purushottam Laud, professor of biostatistics; Elizabeth Smith, biostatistician; Alicia Smallwood, clinical research coordinator; and Dr. Joan Neuner, associate professor of medicine.
The study was funded by grant RSG-11-098-01-CPHPS from the American Cancer Society and grant R01-CA 127648 from the National Institutes of Health.