Added value of the salivary gland ultrasonography OMERACT score in the ACR/EULAR classification criteria for Sjögren's disease

OBJECTIVES: To assess whether addition of the salivary gland ultrasonography (SGUS) OMERACT score influences the performance of the 2016 ACR/EULAR classification criteria for Sjögren's disease (SjD) in daily clinical practice. METHODS: Patients visiting the Sjögren Expertise centre in the University Medical Center Groningen for a diagnostic trajectory because of a suspicion of SjD were included. SGUS was performed of both parotid and submandibular glands. ROC analysis was used to assess the accuracy to predict clinical diagnosis of SjD with the SGUS OMERACT score, and by adding the SGUS OMERACT score to the ACR/EULAR criteria. Furthermore, the performance of the SGUS OMERACT and total SGUS Hocevar score were compared. RESULTS: In total, 419 consecutive patients were included. ROC analysis of the highest SGUS OMERACT score out of all four salivary glands (range 0-3) showed good accuracy (AUC 0.849) to predict clinical diagnosis of SjD, comparable to the accuracy of the total SGUS OMERACT score (range 0-12; AUC 0.868) and total Hocevar score (range 0-48; AUC 0.864). When incorporating the highest SGUS OMERACT score (cut-off score of ≥2) as additional item in the ACR/EULAR criteria, accuracy remained excellent (AUC 0.974), and clinical diagnosis could be predicted with a sensitivity of 96.4% and specificity of 86.5%. CONCLUSION: The accuracy of the ACR/EULAR classification criteria for predicting the clinical diagnosis of SjD remained excellent after incorporating the SGUS OMERACT score and extends the diagnostic options in patients suspected with SjD.