A Study to Learn About the Study Medicine (Called Tofacitinib) in People With Psoriatic Arthritis

The purpose of this study is to learn about the safety and effects of the study medicine for the potential treatment of Psoriatic Arthritis (PsA). Psoriatic Arthritis is a joint swelling disease that can also affect the skin, nails and eyes. The study medicine is called Tofacitinib. This study is seeking participants who: * Started taking tofacitinib alone or with other approved medicines (eg. methotrexate, leflunomide, sulfasalazine, apremilast) for PsA disease. We will only look at participants' who started tofacitinib after December 14, 2017. * Have a 6-month follow-up visit (with a 3-month window) This is an observational study. Participants receiving Tofacitinib will be included to assess how well tofacitinib works. We will look at participants' demographic information and therapy history. We will also monitor participants' disease progression before and 6 months after treatment. We will examine the experiences of people receiving the study medicine. This will help us determine if the study medicine is safe and effective.