Background Achieving minimum clinically effective doses offers major advantages in safety and efficiency.

Purpose To evaluate mean dosage in rheumatoid arthritis (RA) patients treated with adalimumab (ADA), etanercept (ETN) and infliximab (IFX). To correlate these dose strategies with the patient’s disease activity. To estimate annual costs associated.

Materials and Methods Observational, retrospective study. RA patients who received ADA, ETN or IFX for at least 6 months during 2006–2010 were included. Patients could receive different sequential treatments. Mean drug consumption was analysed based on hospital pharmacy service claims and presented as a percentage of the standard RA dose. Escalated and reduced doses were defined as those higher and lower than standard doses. Demographic data, concomitant treatment, disease activity (DAS28-ESR) and antiTNF dosage were analysed. The therapeutic objective was defined as DAS28 < 3.2. Associated annual costs were estimated based on public ex-factory prices including tax (2011 Euros).

Results 198 patients (mean age 60.5 years [±13.06], 80% female, baseline DAS28 = 4.38 [±1.52]). 215 cases: ADA (66 first line, 7 second line), ETN (71 first line, 9 second line, 1 third line), IFX (61 first line).

Conclusions There were no statistical differences regarding baseline disease activity (p > 0.05). Patients in the ADA or IFX groups increased doses above standard doses more frequently than ETN patients (p < 0.05).

There were no differences between groups in percentage of patients with DAS28 < 3.2 (P = 0.927).

AntiTNF real-world data shows significant differences compared to recommended doses, which directly affect treatment costs and efficiency. Measuring efficiency in clinical practise is key for optimization and rational use of biological medicines.

No conflict of interest.