Predictors of inflammatory arthritis among new rheumatology referrals: a cross-sectional study

Early diagnosis and treatment of inflammatory arthritis (IA) is essential to optimize disease control. We aimed to identify variables that distinguish IA from non-inflammatory arthropathy by performing a cross-sectional study of rheumatology referral letters and visit records. Further work describes time to assessment and documentation of variables within referral letters.

We reviewed rheumatology referral letters and new patient visits over a 6-month period. The diagnosis of IA was based on the clinical judgement of the assessing rheumatologist. IA diagnoses included RA, SpAs, unspecified IA, PMR, crystalline arthropathies and remitting seronegative symmetrical synovitis with pitting oedema. Univariate analysis was performed for each variable. Multivariable logistic regression was performed on statistically significant variables.

Of 697 patients referred for arthralgia, 25.7% were diagnosed with IA. Variables predictive of IA included tenderness and swelling on examination and ≥1 h of morning stiffness. Increasing arthralgia duration, fatigue and brain fog were negative predictors. The median time from referral to IA diagnosis was 55 days and 20.7% of these patients were seen within 6 weeks. Among referral letters, documentation of arthralgia duration, morning stiffness or joint examination findings was uncommon (31%, 20.5% and 56.7%, respectively).

We identified positive and negative predictors of IA. Referral letters often missed key information required for the triaging process. Future efforts will be directed towards build a triaging tool to improve the referral quality and capture of those patients with IA who need earlier access to rheumatology care.