We 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.

This registry is a multi-center, prospective, observational program that will gather and analyze data on patients being treated with biologics and targeted synthetic DMARDs in Korea. In contrast to a controlled clinical trial, there is no imposed experimental intervention and solely the patients' physicians will determine the patient's treatment. Thus, the data captured and reported in this registry will reflect a "real world" approach to the treatment with biologics or targeted synthetic DMARDs. There will be no additional visit or laboratory test done outside the routine clinical practice. The selection of the agent, dosing, and treatment duration is determined by the investigator. Informed consent will be obtained from the patient prior to the collection of any data.

Inclusion Criteria:

• Patients diagnosed with RA, AS or PsA
• RA deemed by their rheumatologist to require treatment with a biologic or targeted synthetic DMARDs or a conventional DMARD(s)
• AS or PsA patients who are to initiate, restart or switch to a biologic agent or a targeted synthetic DMARD
• Patients who provide a written consent of participating in this registry (data collection and review).

Exclusion Criteria:

• RA, AS, PsA patients who are already on biologics or targeted synthetic DMARDs upon screening

Patients of the following disease who will initiate, restart or switch to a biologic agent or a targeted synthetic DMARD

1. Rheumatoid arthritis (RA)
2. Ankylosing spondylitis (AS)
3. Psoriatic arthritis (PsA)