AB0367 DIAGNOSTIC DELAY IN PATIENTS WITH GIANT CELL ARTERITIS
Authors: M. Van Nieuwland, E. Colin, D. Boumans, M. Vermeer, E. Brouwer, C. Alves
Journal: Annals of the Rheumatic Diseases (2021)

Background: Giant cell arteritis (GCA) is the most common systemic vasculitis in the elderly which can lead to severe complications when treatment is delayed. Therefore, timely diagnosis and start of treatment is essential. Several forms of delay (consultation, referral and diagnostic delay) can contribute to the total delay towards GCA diagnosis. In the Dutch healthcare system, treatment is not started by a general practitioner (GP). When GCA is suspected, GPs refer to specialists. In our hospital, a fast track clinic (FTC) is used to expedite diagnosis. However, information on factors contributing to delay is scarce. Objectives: The aim of this study was to describe the different components of delay towards diagnosis in GCA suspected patients in a general hospital, Ziekenhuisgroep Twente (the Netherlands). Methods: For this descriptive study, a retrospective cohort consisting of patients with suspected GCA between January 1 st 2017 and October 1 st 2019 was used to analyse components of delay in diagnosis, as suggested by Prior et al. Consultation delay was defined as the time between start of symptoms and a patient’s first consultation with a GP. Referral delay was defined as the time between a patient’s first consultation with a GP and first visit to the FTC. Diagnostic delay was defined as the time between the first visit to the FTC and treatment initiation. Total delay was defined as the time from symptom onset until start of treatment. Delays were described using the median and interquartile ranges (IQR). Results: In our cohort, 206 patients were included for analysis of whom 62 had GCA. Controls (n=144) were suspected of but did not have GCA. Comparing GCA patients with controls, 66.1% and 50.7% were female and the mean (SD) age was 74.2 (9.4) and 70.2 (11.0) years, respectively. In our cohort, the majority of patients (n=42, 67.7%) had cranial GCA (C-GCA). Furthermore, 8 (12.9%) had large vessel GCA (LV-GCA) and 12 (19.4%) had a combination of C-GCA and LV-GCA. For GCA patients, median consultation delay was 2.1 (IQR 0.8-5.8) weeks, referral delay 1.4 (IQR 0.4-4.6) weeks and diagnostic delay 0 (IQR 0-0.1) weeks (Figure 1). For delay regarding consultation and referral, results of controls were comparable to GCA patients. The median total delay was 4.4 weeks (IQR 1.57-10.14) for GCA patients. Conclusion: With a median total delay of 4.4 weeks, delay in our cohort is almost half the delay described in a review by Prior et al. This difference might be due to FTC implementation and subsequent awareness in our hospital and by local GPs. Patients generally received treatment within one day after FTC visit. Nevertheless, contribution of consultation and referral delay is not resolved by introduction of the FTC, as shown in our data. Timely diagnosis is essential as severe complications can develop instantly, which emphasizes the need to tackle consultation and referral delay. References: [1]Prior JA, Ranjbar H, Belcher J, et al. Diagnostic delay for giant cell arteritis – a systematic review and meta-analysis. BMC Med. 2017;15(1):120. Table 1. Baseline characteristics of GCA patients and controls in our retrospective cohort. *CDUS=Colour Doppler Ultrasound; **Temporal Artery Biopsy;***18-FDG-Positron Emission Tomography/Computed Tomography. GCA patients (n=62 ) Controls (n=144 ) Range Range Gender, % female (n) 66.1 (41) 50.7 (73) Age (years), mean (SD) 74.2 (9.4) 51 – 91 70.2 (11.0) 50 – 97 ESR, mean (SD) Missing 78.4 (30.3) 3 22 – 120 39.9 (32.4) 9 2 – 124 CRP, mean (SD) 74.7 (60.0) 2 - 283 35.8 (52.9) 0.4 -280 Missing 1 6 Polymyalgia Rheumatica, % yes (n) 21 (13) 11.8 (17) Cranial symptoms, % yes (n) 80.6 (50) 75.0 (108) Vision loss, %yes (n) Compliant with GCA (i.e. AION, central retinal artery occlusion diplopia ) 27.4 (17) 15.3 (22) Diagnostics CDUS* %yes (n) 96.8 (60) 96.5 (139) TAB** %yes (n) 58.1 (36) 18.8 (27) PET/CT***%yes (n) 40.3 (25) 16.0 (23) Figure 1. Description of consultation (A); referral (B); diagnostic (C) and total (D) delay in weeks for controls (black) and GCA patients (green), stratified for C-GCA (red), LV-GCA (blue) and C/LV-GCA (purple). 1 Not possible for controls as no GCA-indicated treatment was started. Disclosure of Interests: None declared