Prevalence of Giant Cell Arteritis Relapse in Patients Treated With Glucocorticoids: A Meta-Analysis

Objective The relapse rate of patients with giant cell arteritis (GCA) treated with glucocorticoids (GCs) alone varied widely in observational series and randomized controlled trials (RCTs). The purpose of this systematic review was to evaluate the prevalence of relapse and predisposing factors in patients receivingGCs alone. Methods We searched Medline up to December 2017. The prevalence of relapse was pooled using a random-effects model. Results A total of 34 studies (2,505 patients), comprising 8RCTs, were included. The overall prevalence of relapse was 47.2% (95% confidence interval 40.0, 54.3) with a high heterogeneity (I-2= 93%). Prevalence of relapse was significantly higher for patients included in anRCTcompared to those included in an observational study (P< 0.0001), but was not significantly different according to design (P= 0.06). The relapse rate was associated with year of publication (34 studies, rate increase of 8.3% for 1 decade;P< 0.0001) and with shorterGCregimens (17 studies, rate decrease of 1.7% for 1 additional month;P< 0.001), the duration of scheduledGCtherapy being shorter inRCTs (12.8 months) compared to observational studies (28.8 months). The effective duration ofGCtherapy (P= 0.23), initialGCdose (P= 0.49), duration of follow-up (P= 0.14), sex (P= 0.29), and age (P= 0.43) were not associated with the prevalence of relapse. Conclusion GCArelapses occur in half of patients and without improvement across decades in patients receivingGCalone, and the relapse rate is more related to short duration ofGCadministration than to the initial dose at induction. These results advocate for trial design with at least 12 months ofGCtherapy.