Providers’ Perspectives on Diagnostic Testing for Giant Cell Arteritis

Objectives Suspected giant cell arteritis (GCA) is a rheumatologic emergency, but there is no standard pathway for diagnosis at our center. We aimed to improve our understanding of physicians’ experiences with diagnostic testing for GCA and to identify barriers/strategies for improved access.

Methods Specialist providers involved in the diagnosis or treatment of patients with suspected GCA in Edmonton, AB, were invited by email to complete an anonymous survey regarding their experiences requesting and/or performing temporal artery biopsy (TAB), PET/CT, and temporal artery ultrasound (U/S). Descriptive statistics and 1-way ANOVAs were used to analyze the data.

Results In total, 31 physicians from 5 specialties completed the survey. See physician demographics (Table 1). Of the 3 tests, urgent access to TAB was deemed the most essential for diagnosing GCA (with mean score 4.3 ±0.86 on 1-5 point scale; 1=not important, 5=essential) as compared to U/S (mean score 3.9 ±0.79) and PET/CT (mean score 3.40 +/0.82), p=0.004. TAB was most difficult to access, however (mean score 3.8 ±0.52; 1=easy to access, 5=cannot access) as compared to U/S or PET/CT (mean 2.6 ±1.1 and 3.1 ± 0.91, respectively, p<0.001.) Administrative burden was also greatest for TAB (mean score 4.2 ±0.62) vs U/S (2.95± 1.2) or PET/CT (2.95 ±0.89), p<0.001. Overall, 15/20 (75%) rheumatologists/neurologists reported that they either cannot access or find it very challenging to access TAB urgently, particularly for patients without visual involvement. Among 8 surgeons who completed the survey, 6 performed an average of 6-10 TABs/each last year, and 2 did not perform TABs. Scheduling of urgent biopsies, focused scope of practice/lack of capacity, and lack of exposure to procedure in training were cited as surgical barriers. Nuclear medicine physicians read between 21-30 PET/CT scans/each for query GCA last year. The limited number of PET/CT scanners and inability to flag untreated, suspected GCA cases for urgent booking were identified as nuclear medicine barriers. The main reported barrier to TA U/S was that it is currently offered by a single provider only. Overall, 62% (18/29) of all respondents reported being very/somewhat unsatisfied with the process for diagnosing GCA, and only 4/20 (20%) rheumatologists/neurologists reported feeling very confident about their current ability to diagnose/exclude GCA.

Conclusion Providers across multiple specialties were generally unsatisfied with diagnostic testing for GCA, and perceived confidence in ability to accurately diagnose is low (20%.) Increasing the availability of TA U/S may help offset the need for TAB and improve care.