OBJECTIVE: To evaluate the effectiveness and safety of anti-tumor necrosis 
factor (anti-TNF) therapies in rheumatoid arthritis (RA), and to identify the 
factors involved in this response.
METHODS: Dynamic prospective cohort study of patients with RA treated with 
anti-TNF under clinical practice conditions. Effectiveness was evaluated using 
Disease Activity Score (DAS) 28, European League Against Rheumatism (EULAR) 
response, Health Assessment Questionnaire (HAQ), and time to treatment failure. 
Prior adherence was evaluated retrospectively and safety was evaluated by 
adverse events (AE). The analysis was restricted to anti-TNF-naive patients.
RESULTS: The study included 161 patients treated for RA during 6 years (60 
infliximab, 79 etanercept, and 22 adalimumab). At 6 months, 15% reached a good 
EULAR response and 38% a moderate response. A mean decrease of -1.5 (p < 0.0001) 
was observed in the DAS28 and of -0.34 in the HAQ (p < 0.0001); however, women 
showed poorer progress in terms of DAS and HAQ. In the first year, 64.3% did not 
experience treatment failure and this figure was 50.5% after 2 years. In 
one-third, glucocorticoids were withdrawn and in the remainder the dose was 
reduced by 50%. Adherence to treatment, selection of etanercept, and 
intensification of infliximab were associated with a lower probability of 
premature failure in the multivariate model. AE were similar to other those in 
studies and no outstanding differences in safety were found between the 3 
anti-TNF therapies.
CONCLUSIONS: Anti-TNF treatments are effective and safe, reducing the activity 
of the disease, disability, and the need for corticosteroids. Patients who 
displayed good adherence prior to the anti-TNF treatment and were treated with 
etanercept or with increasing doses of infliximab had the best chance of 
displaying a response.