OBJECTIVES: Much information about the disease experience can only be obtained directly from patients.  However, biases may be introduced to patient-reported research depending on the source of the sample.  This analysis seeks to identify differences in demographic and disease characteristics between samples of patients with rheumatoid arthritis (RA) recruited through an advocacy organization and a consumer panel. METHODS: Data were collected online from two groups of patients through self-administered questionnaires.  Patients were recruited through the patient advocacy organization CreakyJoints and the Lightspeed Research consumer panel.  Patients in both groups were U.S. adults (aged ≥18), diagnosed with RA, currently treated by a rheumatologist with disease modifying anti-rheumatic drugs (DMARDs), and with no history of biologic use but had discussed biologics with their physician.  RESULTS: A total of 243 patients completed the study.  Of these, 101 were from the advocacy organization and 142 were from the consumer panel.  Patients from the advocacy organization were younger (mean age, 46 vs. 57) and more likely to be female (93% vs. 80%), employed (53% vs. 31%), have a college degree (59% vs. 43%), and have commercial insurance (70% vs. 51%) than patients from the consumer panel (p<0.05 for all comparisons).  Patients from the advocacy organization also began experiencing RA symptoms more recently (mean years since symptom development, 10 vs. 15) and were more likely to be diagnosed by a rheumatologist (73% vs. 51%), have a caregiver (47% vs. 24%), and be non-adherent with medication (61% vs. 42%) than patients from the consumer panel (p<0.05 for all comparisons). CONCLUSIONS: Members of patient advocacy organizations and consumer panels can differ demographically and in their disease characteristics.  The potential impact of these differences on study results should be considered when developing a sampling and recruitment plan for patient-centered survey research.