HRV Variation in Rheumatoid Arthritis

• Diagnosis of RA meeting 2010 ACR/EULAR classification criteria
• Seropositive or seronegative RA eligible
• Any baseline disease activity (remission/low/moderate/high) to minimize selection bias
• Owns a compatible smartphone (iOS/Android) and is willing/able to use the Oura app
• Willing to wear Oura Ring during sleep throughout study participation (target adherence ≥5 valid nights/week)
• Willing to complete weekly remote assessments and attend baseline and three monthly routine follow-up visits
• Able to read and write English language
• Able to provide written informed consent

Exclusion Criteria:

• Atrial fibrillation or other clinically significant arrhythmias expected to invalidate HRV interpretation
• Implanted pacemaker/defibrillator where HRV measurements are unreliable
• Severe autonomic dysfunction likely to interfere with HRV interpretation (e.g., advanced diabetic autonomic neuropathy), per investigator judgment
• Recent major cardiovascular event within 6 months (e.g., myocardial infarction) or uncontrolled heart failure (NYHA class III-IV), per investigator judgment
• Current use of beta-blockers (excluded due to known autonomic/HRV effects)
• Pregnancy or planned pregnancy during the study period
• Inability to wear the ring reliably (e.g., occupational restrictions or hand deformity preventing wear)
• Participation in another interventional clinical trial likely to confound outcomes