(HealthDay) -- The prevalence of older people with cancer using complementary medications as they start a chemotherapy regimen is 17 percent, and is associated with less advanced disease and higher functional status, according to a study published online Feb. 22 in Cancer.

Ronald J. Maggiore, M.D., of the University of Chicago Medical Center, and colleagues evaluated the prevalence of complementary medicine use as well as factors associated with its use among 545 patients (mean age, 73 years) about to start chemotherapy for cancer (61 percent stage IV).

The researchers found that 17 percent of patients reported using at least one complementary medication, with a mean of two medications used per patient. There was an association between complementary medication use and earlier (stage I to II, 29 percent; stage III to IV, 17 percent; odds ratio [OR], 2.05) as well as less impairment in instrumental activities of daily living (OR, 1.39).

"Complementary medication use was reported by 17 percent of older adults with cancer and was more common among those who had less advanced disease (i.e., those receiving adjuvant, potentially curative treatment) and higher functional status," the authors write. "Further studies are needed to determine the association between complementary medication use and cancer outcomes among ."

One of the authors disclosed to the pharmaceutical industry.