(HealthDay)—For patients with rheumatoid arthritis (RA), prednisone use is associated with an increased risk of mortality, according to a study published in the May issue of Arthritis Care & Research.

Mary Chester Wasko, M.D., from the Allegheny Health Network in Pittsburgh, Pa., and colleagues conducted a prospective study involving 5,626 RA patients followed for up to 25 years. The authors examined the risk of death associated with prednisone use alone and combined treatment of prednisone with methotrexate or sulfasalazine.

The researchers found that during a median follow-up of 4.97 years, 11.8 percent of patients died. Prednisone use was associated with increased risk of death in a multivariate, propensity-adjusted model (hazard ratio, 2.83; 95 percent confidence interval, 1.03 to 7.76). There was a significant interaction between prednisone use and methotrexate use (P = 0.03), with the risk of death attenuated for patients treated with and methotrexate (hazard ratio, 0.99; 95 percent confidence interval, 0.18 to 5.36). The protective association of methotrexate with mortality was weakened with combination treatment. Similar results were seen for sulfasalazine.

"Prednisone use was associated with a significantly increased risk of mortality in patients with RA," the authors write. "This association was mitigated by concomitant disease-modifying antirheumatic drug use, but combined treatment also negated the previously reported beneficial association of methotrexate with survival in RA."