Adherence to therapy for patients treated with etanercept. The level of adherence to therapy is shown as the fraction (between 1 and 0) of patients remaining on therapy during the observation period. Withdrawal due to any reason (a), adverse events (b), or failure to treatment (c) is presented separately. The number of patients under observation at each time point is listed at the bottom of the figure. DMARD, disease-modifying antirheumatic drug.