NOR-DMARD is a register-based longitudinal observational study of which the main objectives are to study the effectiveness of treatment of inflammatory joint diseases with biological disease modifying anti-rheumatic drugs (DMARDs) in clinical practice, by measuring disease activity, health related quality of life, function and joint damage, and to study the long-term safety of such treatment. Other objectives include the assessment of cost-effectiveness of treatment, to identify and and validate clinical, genetic and immunological predictors of efficacy and adverse events, to assess the impact of treatment with biological DMARDs on work participation and work productivity, to investigate different strategies for use of biological DMARDs, to assess the performance of different outcome measures, and to ensure a systematic and timely follow-up of patients treated with biological DMARDs.

This study is a modification, and an extension, of the NOR-DMARD study that was conducted in 5 Norwegian rheumatology departments in the period 2000-2012. The study includes a structured follow-up with study visits at baseline (start of biological drug) and after 3, 6, 12 months and every 12 months thereafter. Each study visit includes clinical assessment, patient-reported outcomes and measurement of acute-phase reactants. The data collection also includes blood samples for biobank at baseline and 3 months. Serious adverse events data will be systematically recorded, but other adverse events can also be retrieved by linkage to other registers.

Inclusion Criteria:

• Age >18 years
• Diagnosis of rheumatoid arthritis, psoriatic arthritis, ankylosing spondylitis, spondyloarthritis, adult juvenile idiopathic arthritis, undifferentiated arthritis, or any other inflammatory arthritis
• Clinical indication to start a new treatment with a biological disease modifying anti-rheumatic drug or a kinase inhibitor

Exclusion Criteria:

• Unwillingness or unability to give written informed consent
• Psychiatric or mental disorders, alcohol abuse or other abuse of substances, language barriers or other factors which makes adherence to the study protocol impossible
• Participation in blinded RCTs or other studies incompatible with the NOR-DMARD study protocol

Adult patients with inflammatory arthropathies starting a new treatment with a biological disease modifying anti-rheumatic drug