Objective: To clarify the spontaneous course of important disease manifestations (a core set of outcome measures) over a period of 5 years in patients with primary Sjögren's syndrome (SS), and to analyze predictors of unfavorable outcome. To test the usefulness of the recently proposed core set of outcome measures.
Methods: A cohort of patients with primary SS according to the American-European consensus criteria (AECC) (n = 58) was followed over a period of 5 years. Measures for subjective and objective disease characteristics, IgG concentrations and health related quality of life were analyzed on 2 occasions and compared.
Results: During followup, symptoms of dry eyes, dry mouth, fatigue, and health related quality of life were stable. Regarding objective signs, there was a modest but statistically significant worsening of the van Bijsterveld score. Seropositivity for anti-SSA and low complement levels predicted further decline in the van Bijsterveld score. Floor/ceiling effects in the outcome measures in the core set complicate documentation of further decline, but may allow monitoring of improvement in established primary SS.
Conclusion: Primary SS, if classified according to the strict AECC criteria, is a bothersome and slowly progressive disease, with fatigue and discomfort developing early. The proposed outcome measures may be suitable for assessing improvement in randomized controlled trials.