To evaluate the longterm effectiveness of disease modifying antirheumatic drugs (DMARD) in an inception cohort of patients with rheumatoid arthritis (RA) seen by rheumatologists.
We performed a retrospective audit of the records of patients with onset of RA between January 1985 and June 1994. Charts were reviewed from the time of diagnosis to the last consult. Survival analysis was performed using Kaplan-Meier and Cox proportional hazard regression to adjust for potential confounders.
A total of 2296 DMARD therapies were analyzed. Roughly half were started within 2 years of disease onset. By 16 months, 50% of the DMARD therapy courses had been discontinued, and after 4.5 years 75% had been discontinued. Over all, methotrexate (MTX) had the highest probability of continuation. After roughly 3 years 50% of patients were still receiving MTX, compared to one-third of patients who received antimalarials or intramuscular gold, 30% D-penicillamine, 25% sulfasalazine, and 18% oral gold. After 6 years, when considering all DMARD together, only 20% of the therapies had not been discontinued, with no substantial differences between drugs. Toxicity from gold compounds occurred within the first 18 months of therapy and stabilized thereafter. For MTX, withdrawals due to toxicity continued throughout therapy.
This is the largest observational study examining the longterm termination rates of DMARD in patients followed from the time of their initial consult. Our results confirm previous reports of short therapeutic times, even for patients treated early in the course of their disease. MTX appears to be the best drug within the first 5 years of disease. These differences, however, decrease in the longer term. It is unclear whether the results observed for MTX within the first years of therapy translate to better health status in the longer term when compared to other DMARD.