The main objective is to assess Health-Related Quality of Life (HRQoL) according to physical function, as measured by a specific Questionnaire (Health Assessment Questionnaire), in Rheumatoid Arthritis (RA) patients who begin therapy with subcutaneous Anti-Tumour Necrosis Factor alpha (TNFα) Certolizumab Pegol (CZP).
Inclusion Criteria: * Patient is male or female, aged 18 years or older * Patient has active Rheumatoid Arthritis according to American College of Rheumatology (ACR) criteria with duration ≥ 3 months * Patient has DAS28 (ESR) \> 4.5 and CRP \> 1.0 mg/dl at Baseline * Patient has failed previous Disease Modifying Anti-Rheumatic Drugs (DMARDs) including Methotrexate treatment * Patient has initiated treatment with subcutaneous anti-Tumour Necrosis Factor alpha (anti-TNFα) CZP, administered every 2 weeks * Patient has no other prior anti-TNFα treatment (Naïve Patient) or CZP is administered after failure to the first anti-TNFα treatment (First Switch Patient) * Patient is considered reliable and capable of adhering to the protocol, visit schedule or medication intake according to the judgment of the physician * Patient has signed and dated a written informed consent form * The patient's treatment must be within the terms of Summary of Product Characteristics (SmPC) Exclusion Criteria: * Patient has a known hypersensitivity to the active substance or to any of the excipients * Patient has active Tuberculosis or other severe infections such as Sepsis or Opportunistic Infections * Patient has moderate to severe Heart Failure (New York Heart Association (NHYA) classes III/IV) * Patient has any medical or psychiatric condition that, in the opinion of the physician, could jeopardize or would compromise the patient's ability to participate in this study or to complete the scheduled questionnaires * Pregnant women or women of childbearing potential who are not using adequate contraception to prevent pregnancy