[Critical overview of outcome parameters for patients with primary Sjögren's syndrome].

Not only in the context of clinical trials in particular, but also in daily clinical practice, outcome parameters or measuring instruments are essential to assess the efficacy of a therapeutic intervention, its influence on disease activity and potentially also to predict further disease course. Such criteria can assist in the identification of patient risk groups that may require special checkups or interventions. Moreover, these parameters should be reliable, objective and valid, e.g. to allow comparison of results from different studies. Therefore, outcome parameters need to be developed and/or validated in a targeted manner for individual diseases or investigations. To date, we have only limited therapeutic options for Sjögren's syndrome, a frequent systemic autoimmune disorder of unknown origin. Against the background of the new therapy approaches expected, this article provides a critical overview of available and newly developed outcome parameters for patients with Sjögren's syndrome.