China rheumatoid arthritis registry of patients with Chinese medicine (CERTAIN): Rationale, design, and baseline characteristics of the first 11,764 enrollees.

Background: Chinese medicine (CM) has become a popular interventional treatment for rheumatoid arthritis (RA). However, limited knowledge about general characteristics and long-term clinical outcomes hampers the development of CM for RA.

Purpose: The main objectives of the China Rheumatoid Arthritis Registry of Patients with Chinese Medicine (CERTAIN) were to describe the population of RA patients receiving CM treatment in multiple centers in China using different variables and compare these findings with internationally reported data.

Study Design: The CERTAIN is a prospective, multicenter, observational disease registry.

Methods: Adult RA patients who fulfilled the 2010 American College of Rheumatology/ European League Against Rheumatism classification criteria for RA and received CM treatment were recruited into the CERTAIN by rheumatologists from 145 hospitals across 30 provinces in China. Data on demographics, disease characteristics, comorbidities, treatments, and adverse events, with a 2-year follow-up, were collected and documented using a predefined protocol.

Results: In the 2 years since the study began in September 2019, 11,764 patients have been enrolled (enrolment is ongoing), and 13.10% of participants have completed the 6-month follow-up. We present the baseline characteristics of the first 11,764 enrollees.

Conclusions: The CERTAIN is the first nationwide registry to document comprehensive data on CM treatment in patients with RA. The development of the CERTAIN resource is a significant step forward for Chinese RA patients, herbal medicine users, and research communities and will deepen our understanding of CM for RA.

Registration: The study was registered at ClinicalTrials.gov (NCT05219214).