Sjögren's Syndrome Disease Damage Index and Disease Activity Index.

The article presents a study that developed valid instruments for the assessment of disease-related damage and disease activity in Sjögren's syndrome (SS). The results indicate that the Sjögren's Syndrome Disease Damage Index (SSDDI) is an adequate instrument to objectively measure damage in patients with SS. The study also found that the Sjögren's Syndrome Disease Activity Index (SSDAI) is a valid tool to measure disease activity when used either as a single-state index or a transition index.