Measures of arthritis activity associated with patient-reported improvement in rheumatoid arthritis when assessed prospectively versus retrospectively

Abstract

Objective The patient global assessment (PGA) is intended to provide an integrated summary of all symptoms of arthritis, but it is not clear which disease features most impact patients' assessments of changes in their overall status. We investigated what aspects of rheumatoid arthritis (RA) activity correlated best with prospectively measured changes in the PGA and with patients' retrospective judgments of improvement. Methods We studied 250 patients with active RA in a prospective longitudinal study. Disease activity measures were collected before and after treatment escalation. Prospectively measured changes in PGA and patients' judgments of improvement or worsening at the followup visit were tested for correlations with changes in patient-reported measures of symptoms and functioning, joint counts, and laboratory tests. Results Patients improved during the study, with the mean±SD PGA decreasing from 55.6±25.2 to 37.6±24.0. At the followup visit, 167 patients (66.8%) reported improvement in overall arthritis status. Changes in pain severity, stiffness severity, and fatigue were the only significant correlates of changes in PGA. In contrast, changes in the Health Assessment Questionnaire, tender joint count or Disease Activity Score in 28 joints (DAS28), and stiffness severity were associated with retrospective judgments of improvement. Conclusion Prospectively measured changes in PGA in RA were related solely to other patient-reported measures, but patients' retrospective judgments of improvement were related to functional limitations, tender joint count, and DAS28. Patients' subjective judgments of improvement reflect aspects of RA different from the PGA and may be a simple complementary measure of treatment efficacy.