Giant Cell Arteritis: A Systematic Review and Meta‐Analysis of Test Accuracy and Benefits and Harms of Common Treatments

This systematic review compares treatment options for patients with giant cell arteritis (GCA) and evaluates the test accuracy of studies used in diagnosing and monitoring GCA. These studies were used to inform evidence‐based recommendations for the American College of Rheumatology (ACR)/Vasculitis Foundation (VF) vasculitis management guidelines. A systematic review and search of articles in English in Ovid Medline, PubMed, Embase, and the Cochrane Library was conducted. Articles were screened for suitability, and studies presenting the highest level of evidence were given preference. Three hundred ninety‐nine full‐text articles addressing GCA questions were reviewed to inform 27 Population, Intervention, Comparison, and Outcome questions. No benefit was found with intravenous glucocorticoids (GCs) compared with high‐dose oral GCs in patients with cranial ischemic symptoms (27.4% vs 12.3%; odds ratio [OR] 2.39 [95% confidence interval (CI) 0.75‐7.62], [very low certainty of evidence]). Weekly tocilizumab with a 26‐week GC taper was superior to a 52‐week GC taper in patients achieving remission (risk ratio 4.00 [95% CI 1.97‐8.12], [low certainty of evidence]). Non‐GC immunosuppressive therapies with GCs compared with GCs alone showed no statistically significant in relapse at 1 year (OR 0.87 [95% CI 0.73‐1.04], [moderate certainty of evidence]) or serious adverse events (OR 0.81 [95% CI 0.54‐1.20]; [moderate certainty of evidence]). Temporal artery biopsy has a sensitivity of 61% (95% CI 38%‐79%) and a specificity of 98% (95% CI 95%‐99%) in patients with a clinical diagnosis of suspected GCA. This comprehensive systematic review synthesizes and evaluates the benefits and harms of different treatment options and the accuracy of commonly used tests for the diagnosis and monitoring of GCA.