Predicting the future development of spondyloarthritis among patients with idiopathic acute anterior uveitis using real-world data
Muhammad Haroon (1), Keith A. Betts (2), Fan Mu (2), Martha Skup (3), Jaclyn K. Anderson (3), Avani D. Joshi (3)
1. Division of Rheumatology, University Hospital Kerry, Tralee, Ireland; 2. Analysis Group, Boston, MA, USA; 3. AbbVie Inc., North Chicago, IL, USA
At least 40% of idiopathic AAU patients have undiagnosed SpA. However, the clinical factors to predict the incident diagnosis or future development of SpA remain poorly understood.
The objectives of this study were: 1) To describe the patient characteristics of AAU patients with and without SpA diagnosis, and 2) To identify the predictive factors of SpA diagnosis among AAU patients using real-world data.
Data were extracted from the Truven Health MarketScan Commercial Claims Encounters database and the Medicare Supplemental database from USA. Data period Q1 2008 to Q2 2015 was used for analysis. Index date was the date of first AAU diagnosis. Patients included in the analysis were grouped into two cohorts: 1) Patients with SpA: AAU patients with at least one SpA diagnosis post index date, 2) Patients without SpA: AAU patients without any SpA diagnosis post index date. Figure-1 describes the study design. Number of clinical characteristics were measured during the 6-month baseline period. SpA diagnosis was assessed after the index date. Baseline factors predictive of SpA diagnosis were selected into a multivariable Cox proportional hazards model based on statistical significance, magnitude of hazard ratios (HR), and clinical relevance.
A total of 48,822 patients with AAU were included (Figure-2). Among them, 1,032 patients were newly diagnosed with SpA and 47,790 patients did not have any SpA diagnosis during the follow-up period. Using Cox Proportional Hazards Models of SpA diagnosis among adult AAU patients, the most predictive factors of SpA diagnosis were male, age<45 years, recurrent AAU, back pain, inflammatory bowel disease and psoriasis. To the best of our knowledge, this is the first study to identify the risk factors of future SpA diagnosis among AAU patients.
There are significant differences among isolated AAU patients and AAU patients that developed SpA later. Since delayed diagnosis is common among SpA patients, identifying such predictive factors can help inform risk stratification.