Mortality in rheumatoid arthritis patients treated with or without methotrexate

Rheumatoid arthritis (RA) is a chronic disease associated with excess mortality. In 1974 a registry of RA patients was established at the Wichita Arthritis Center. It has been directed by its founder, Dr. Frederick Wolfe, ever since. The database for RA patients provided results for the present study and 1 of the 4 series reported previously.

These are based on a consecutive series (after specific exclusions) of RA patients, 18 years of age and older, treated at the Wichita Arthritis Center, 1981 through 1999. During this period, 588 of the total 1240 RA patients were treated with methotrexate, and 652 patients did not receive any methotrexate. Total exposure amounted to 7584 patient-years, and total deaths numbered 191. An elaborate statistical method was developed by Wolfe and a team of Harvard epidemiologists to adjust for prognostic risk factors, which were higher in the methotrexate than in the non-methotrexate group. Detailed descriptive data were included in the database. Overall excess mortality in comparison with population rates was higher in the methotrexate than in the non-methotrexate group, but the unadjusted difference was not significant. Results for the 1981-1999 total Wichita cohort were compared with those of the 1974-1990 cohort and the 1983 Impairment Study (both before and after adjustment to the older age distribution of the Wichita patients).

Mortality improved somewhat in the RA patients at the Wichita Center from 1974-1990 to 1980-1999. In the later period, mortality was lower in patients treated with methotrexate than in those not so treated. After the authors of the source article made adjustments for the increased RA severity in the patients treated with methotrexate, mortality was significantly lower in the methotrexate-treated group, with a mortality hazard ratio of 0.4 (95% confidence interval 0.2-0.8).