Grøn KL, Glintborg B, Nørgaard M, et al. - In this observational cohort study following a randomized trial (using intent-to-treat analyses), investigators intended to evaluate compliance with guidelines (supporting the assumption of surrogate randomization) and to contrast the efficiency of certolizumab pegol (CZP), abatacept (ABA), and biosimilar infliximab (CT-P13) in individuals treated according to guidelines. Seven hundred seventy-six people were recruited in the study and randomized to CZP (n = 336), ABA (n = 215), and CT-P13 (n = 225). The surrogate randomization procedure allowed head-to-head comparisons of CZP, ABA, and CT-P13. However, some variations in predicted efficiency were noted across drugs, confidence intervals were extensive and statistical importance was not relinquished.