Serious infections and BioDMARDs: what is the confounding factor? BSRBR-RA: 33,916 RA treated w/ BioDMARDs with 62,532 years of follow-up, 2036 SI. HR of SI no longer different among BioDMARDs when adjusted for the line of therapy! #OP0241@Rheumnow #EULAR2021 https://t.co/UG9WrXP7RD