RecruitingDrug trialKorean College of Rheumatology Biologics and Targeted Therapy RegistryWe established a nationwide biologics and targeted synthetic DMARDs registry (in the form of an inception cohort) to study the safety profiles in rheumatoid arthritis, ankylosing spondylitis and psoriatic arthritis patients receiving biologics or targeted synthetic DMARDs. As this registry is to observe the "real world" use of anti-rheumatic treatments under routine clinical practice, no hypothesis to prove is planned.