Dr. Wasko has served as site principal investigator for Centocor trials and as a consultant to UCB and Centocor.
Propensity-adjusted association of methotrexate with overall survival in rheumatoid arthritis
Article first published online: 28 JAN 2013
Copyright © 2013 by the American College of Rheumatology
Arthritis & Rheumatism
Volume 65, Issue 2, pages 334–342, February 2013
How to Cite
Wasko, M. C. M., Dasgupta, A., Hubert, H., Fries, J. F. and Ward, M. M. (2013), Propensity-adjusted association of methotrexate with overall survival in rheumatoid arthritis. Arthritis & Rheumatism, 65: 334–342. doi: 10.1002/art.37723
- Issue published online: 28 JAN 2013
- Article first published online: 28 JAN 2013
- Accepted manuscript online: 8 OCT 2012 12:14PM EST
- Manuscript Accepted: 25 SEP 2012
- Manuscript Received: 13 DEC 2011
- NIH (National Institute of Arthritis and Musculoskeletal and Skin Diseases). Grant Number: AR-43584
- Intramural Research Program
Vol. 65, Issue 5, 1231, Article first published online: 23 APR 2013
While medications used to treat rheumatoid arthritis (RA) may affect survival in RA, few studies take into account the propensity for medication use, which may reflect selection bias in treatment allocation in survival models. We undertook this study to examine the relationship between methotrexate (MTX) use and mortality in RA, after controlling for individual propensity scores for MTX use.
We studied 5,626 RA patients prospectively for 25 years to determine the risk of death associated with MTX use, modeled in time-varying Cox regression models. We used the random forest method to generate individual propensity scores for MTX use at study entry and during followup in a time-varying manner; these scores were included in the multivariate model. We also investigated whether selective discontinuation of MTX immediately prior to death altered the risk of mortality, and we examined the association of duration of MTX use with survival.
During followup, 666 patients (12%) died. MTX use was associated with reduced risk of death (adjusted hazard ratio 0.30 [95% confidence interval 0.09–1.03]). Selective MTX cessation immediately before death did not account for the protective association of MTX use with mortality. Only MTX use for >1 year was associated with lower risks of mortality, but associations were not stronger with longer durations of use.
MTX use was associated with a 70% reduction in mortality in RA.