Clinical Trials

Clinical trials are research studies involving patients to evaluate the effectiveness of health interventions. The interventions may be new treatments including drugs, behavioural therapies or alternative or new methods of diagnosis. A clinical trial may proceed through four phases:

  • Phase I. The trial involves a small group (20-100) of healthy individuals to evaluate the safety of the intervention (e.g. to determine safe dose range and side effects);
  • Phase II. The trial involves a group (100-300) of patients to test for efficacy (e.g. therapeutic dosage) and safety;
  • Phase III. The trial involves a larger group of patients (1000-2000) to confirm effectiveness, to monitor side effects, and to compare the new treatment to commonly used treatments;
  • Phase IV. Phase IV is sometimes referred to as Post-market Surveillance. The trial is conducted after the treatment is being used to monitor for long-term effects.

The Arthritis Society does not recruit volunteers directly for clinical trials. For those interested in learning more about clinical trials or volunteering for a clinical trial, a few resources are listed below.

  1. a registry of clinical trials being conducted in the United States and around the world (;
  2. World Health Organization International Clinical Trials Registry Platform (; 
  3. For more general information on clinical trials (;
  4. Additional information: