Clinimetric methods in Sjögren's syndrome

Abstract

Objective: Clinimetric tools are useful in both clinical practice and research of Sjögren's syndrome. These instruments assist in the establishment of diagnosis and in the evaluation of disease status. We reviewed the available methods used to monitor sicca signs and symptoms, fatigue, quality of life as well as activity/chronicity in SS.

Methods: PubMed and MEDLINE database were searched for the keywords "keratoconjunctivitis sicca diagnosis," "dry eye and dry mouth assessment," "sialometry," "sialochemistry," "Sjögren's syndrome outcomes," "Sjögren's syndrome activity," "Sjögren's syndrome damage," "fatigue scales in Sjögren's syndrome," and "Sjögren's syndrome quality of life." All relevant articles and pertinent secondary references were reviewed.

Results: As there is a moderate correlation between sicca symptoms and signs, the assessment of both is crucial. Most of the tests focus on oral and ocular dryness (vital dye staining, tear quantification, tear composition, sialometry, sialochemistry, etc.) and may not be disease specific. Symptoms such as dryness and fatigue have been evaluated with different instruments, being the PROFAD and ESSPRI disease-specific tools. Standardized measures for activity (SSDAI, SCAI, and ESSDAI) and chronicity (SSDDI and SSDI) indexes are currently used, however these methods still present limitations such as low external validity and cross-validation.

Conclusion: The heterogeneous nature of the disease and its slow progression, challenge the evaluation of these patients. The use of composite measures might increase our ability to diagnose and evaluate disease activity and cumulative irreversible organ injury in this disease. However the distinction among oral and ocular activity vs. damage is still a matter of research.