Eligibility Criteria

The A3BC includes children and adults with inflammatory arthritis, autoimmune disease, related conditions, and selected comparator participants. Eligibility is confirmed through discussion between participants, families and treating clinicians.

Inclusion criteria

You may be eligible to take part if you:

  • Are of any gender
  • Aged 0–18 years for juvenile‑onset arthritis, autoimmune or inflammatory diseases, or
  • Aged 18 years or older for adult inflammatory, autoimmune or musculoskeletal conditions
  • Have a diagnosis confirmed by a rheumatologist or other relevant specialist under validated classification criteria, or meet criteria for an approved at‑risk or comparator cohort
  • Are willing for your treating clinician to be notified of your participation (where applicable)
  • Are able (in your treating clinician’s opinion) and willing to comply with study requirements
  • Are willing and able to provide informed consent for participation (or have consent provided by a parent or guardian, where applicable)

Comparator (control) participants without a diagnosed inflammatory or autoimmune disease may also be eligible for selected studies.

Exclusion criteria

You may not be eligible to take part if:

  • You are unable to understand the consent process, and do not have access to an interpreter or other support to enable informed consent
  • You have a medical, cognitive or other condition which, in the opinion of the treating clinician, would:
    • place you at risk by participating, or
    • significantly limit your ability to participate (e.g. complete questionnaires)
  • Existing (“legacy”) samples or data do not meet current A3BC ethical, consent or standard operating procedure requirements

Eligibility may vary slightly for specific sub‑studies or projects. The A3BC team can help confirm eligibility before consent.

Cohorts in A3BC

The A3BC includes people at different stages of arthritis and autoimmune disease, as well as people without a diagnosis who wish to contribute as comparison participants. During enrolment, we ask a small number of questions to help place participants into one or more research cohorts.

These cohorts help researchers understand:

  • How disease begins and progresses
  • How treatments work at different stages
  • Why some people respond well to treatment and others do not
  • Who may be able to safely reduce or stop medication

Your answers do not affect your clinical care and are used only for ethically approved research.

How enrolment questions are used

The following questions help the A3BC team understand which cohorts may be most relevant for you. You may belong to more than one cohort over time.

General information

These questions help ensure appropriate consent and analysis:

  • Sex assigned at birth
  • Age

Diagnosed disease cohorts

These questions identify your main condition and whether you are under specialist care:

  • Have you been diagnosed with any of the following conditions?
    (e.g. Rheumatoid Arthritis, Psoriatic Arthritis, Ankylosing Spondylitis / Spondyloarthritis, Juvenile Idiopathic Arthritis, Polymyalgia Rheumatica, Giant Cell Arteritis)
  • Do you see a rheumatologist for the management of your condition?

These responses help assign participants to disease‑specific cohorts.

At‑risk and early disease cohorts

These questions help identify people at earlier or pre‑clinical stages of disease:

  • Do you have joint symptoms (pain, stiffness or swelling) that started within the past 12 months?
  • Have you ever been told you tested positive for autoimmune antibodies (e.g. ACPA or RF)?
  • Do you have a first‑degree relative (parent, sibling or child) with autoimmune or inflammatory arthritis?

These answers help identify participants suitable for:

  • At‑risk / pre‑clinical cohorts
  • Early disease cohorts

Treatment pathway cohorts

These questions relate to changes in treatment and help support research into medication effectiveness:

  • Are you about to start a new medication (e.g. a DMARD)?
    → Starting treatment cohort
  • Are you about to change medications because of lack of effect, side effects or a flare?
    → Switching treatment cohort

Disease control and difficult‑to‑treat cohorts

These questions help understand long‑term outcomes and unmet need:

  • Is your condition currently well‑controlled (e.g. in remission or low disease activity)?
  • Do you or your rheumatologist find your disease difficult to manage?

These responses help identify:

  • Stable disease cohorts
  • Difficult‑to‑treat disease cohorts

Tapering and stopping treatment cohorts

These questions support research into safe medication reduction:

  • Are you planning to reduce or stop your arthritis or autoimmune medication as part of your usual care?

This helps identify participants suitable for:

  • Tapering treatment cohorts
  • Stopping treatment cohorts

Comparator (control) cohort

For participants without a diagnosed inflammatory or autoimmune disease:

  • If you have no known personal history of autoimmune disease or inflammatory arthritis, are you interested in participating as a healthy control?

Comparator participants help researchers better understand what is specific to disease and what is not.

Important to know

  • You may belong to more than one cohort over time
  • Being in a cohort does not change your clinical care
  • Answering “yes” does not enrol you into a trial — it only helps identify research relevance

All information is handled securely and used only in accordance with your consent and ethics approval.