Rheumatoid Arthritis referral criteria: systematic review of the literature

INTRODUCTION: Timely referral in Rheumatoid Arthritis (RA) is critical for early diagnosis and initiation of treatment, which are crucial to improve patient outcomes and limit radiographic progression. Optimized referral criteria, whether applied by clinicians or healthcare artificial intelligence systems, can facilitate faster and more accurate decisions regarding patient assessment by a Rheumatologist. Despite this need, a validated and widely adopted referral tool for RA is still lacking. OBJECTIVE: To compile and analyse all available RA referral criteria since January 2001 until October 2023. METHODS: We searched PubMed, Scopus and Web of Science in the considered period, using a defined set of strings. Studies were only included if they provided RA referral criteria or Inflammatory/Early Arthritis criteria directed at RA diagnosis. RESULTS: We identified 19 publications. Most include symptoms in referral criteria, either arthralgia or stiffness (63%) and only 16% considered constitutional symptoms such as fever, fatigue or weight loss. However, the most prevalent criteria for referral is swollen joints (79%), while tender joints are included in 63% and squeeze test assessment in 33%. Regarding laboratory tests, rheumatoid factor is considered in 53% of referral criteria, while ACPA in 32%. Nearly half of the referral criteria consider inflammatory markers (CRP and/or ESR). Family history is present in 21% of the cases. DISCUSSION: Published RA referral criteria encompass several components (symptoms, signs, laboratory and family history), but none were validated in a large cohort of patients. The vast majority, were either part of recommendations, published guidelines or based in expert opinion. There is an unmet need for evidence-based validated RA referral criteria. PROSPERO REGISTER: CRD42024499423.