Determinants of patient and physician global assessments of disease activity in anti-neutrophil cytoplasmic antibody-associated vasculitis

There has been a marked increase in the past 15 years in the number and quality of clinical trials in the idiopathic inflammatory vasculitides, especially the small-vessel vasculitides known as antineutrophil cytoplasmic autoantibody (ANCA)-associated vasculitis [AAV; granulomatosis, with polyangiitis (Wegener's)]. These trials have been conducted by multicenter, international groups in Europe and the United States with financial support provided by government agencies and biopharmaceutical companies. This increased clinical trial activity in vasculitis has been accompanied by the development and validation of new outcome measures--a challenging process for these complex, multiorgan system diseases. The international OMERACT Vasculitis Working Group has developed and implemented an iterative research agenda that has utilized accumulated experience and datasets from several multicenter clinical trials and large cohort studies. This work has led to the development, evaluation, validation, and endorsement, through the OMERACT consensus and validation processes, of a "core set" of outcome measurements for use in clinical trials of AAV. The core set includes domains of disease activity, damage assessment, patient-reported outcomes, and mortality; there is at least one validated outcome measurement instrument available for each domain. This report reviews the domains of illness in AAV included in the OMERACT core set, describes the instruments validated to measure these domains, and presents the approved core set.

The goal of this work was to develop an economical way of tracking disease activity for large groups of systemic lupus erythematosus (SLE) patients in clinical studies. A Systemic Lupus Activity Questionnaire (SLAQ) was developed to screen for possible disease activity using items from the Systemic Lupus Activity Measure (SLAM) and tested for its measurement properties. The SLAQ was completed by 93 SLE patients just prior to a scheduled visit. At the visit, a rheumatologist, blinded to SLAQ results, examined the subject and completed a SLAM. Associations among SLAQ, and SLAM (omitting laboratory items) and between individual items from each instrument were assessed with Pearson correlations. Correlations between pairs of instruments were compared using Student's t-tests. The mean score across all 24 SLAQ items was 11.5 (range 0-33); mean SLAM without labs was 3.0 (range 0-13). The SLAQ had a moderately high correlation with SLAM-nolab (r = 0.62, P < 0.0001). Correlations between patient-clinician matched pairs of items ranged from r = 0.06 to 0.71. Positive predictive values for the SLAQ ranged from 56 to 89% for detecting clinically significant disease activity. In studies of SLE, symptoms suggesting disease can be screened by self-report using the SLAQ and then verified by further evaluation.