62. Characterisation of systemic vasculitis outcomes across a nation: do different models of care matter?
Creators: name: Enock Havyarimana1
name: Rutherford1, Matthew
name: James2, Warren
name: Corri Black2
name: Basu1, Neil
name: Hollick3, Rosemary
Publisher: name: Zenodo
Year: 2022
Subjects: Vasculitis
ANCA
Abstracts
Giant Cell Arthritis
MPA
GPA
EGPA
Takayasu
IgA vasculitis

description: <strong>Background/Objectives:</strong> Care models employed to manage systemic vasculitis typically vary between regional health care systems. It is unknown if such differences result in geographical variation in outcomes. In this population based national study of individuals with ANCA associated vasculitis (AAV) and Giant Cell Arteritis (GCA) we aimed to explore geographical variation in key outcomes across the nation of Scotland where variation in regional vasculitis care models are known to exist. <strong>Methods</strong>: Patients’ ≥16 years with ≥ 1 ICD-10 code for AAV [Granulomatosis with Polyangiitis (GPA) - M31.3; Microscopic Polyangiitis (MPA) - M31.7; Eosinophilic granulomatosis with polyangiitis (EGPA) - M30.1] or GCA [M31.5 and M31.6] between 1996 and 2021 were identified from the population based Scottish hospitalisation registry (&gt;90% population coverage). Each patient was matched with up to 5 general population controls (with a previous record of hospital admission) by age (+/-2 years), sex and health service region of residence. Incidence rates of serious infection, cardiovascular and cancer rates for AAV and GCA cohorts compared to matched controls were analysed using Poisson regression, adjusted for age, sex, deprivation and population density metrics. In each cohort, a stratified analysis per health board of treatment compared incident rate ratios (IRRs) for clinical outcomes across health service regions in Scotland, to the national average. We assessed heterogeneity in outcomes between health service regions using I<sup>2</sup> (index of heterogeneity). <strong>Results:</strong> A total of 1943 patients with AAV (median age 61.2 years [IQR 49.5 – 70.9]; 50.2% male) and 9715 population controls (median age 61.3 years [IQR 49.4-70.7]; male 50.2%) were identified with a median follow up time of 6.6 and 8.4 years respectively. Risk of serious infection requiring hospital admission, cardiovascular disease and cancer was higher in AAV patients than in matched controls (serious infection: IRR 2.24 [95% confidence interval (CI) 1.91, 2.62]; cardiovascular disease: IRR 1.98 [95% CI 1.65, 2.38]; cancer: IRR 1.78 [95% CI 1.60, 1.98]. 7107 patients with GCA (median age 75.2 years [IQR 68.1-81.3]; 28.2% male) and 10,030 hospital controls (median age 75.3 years [IQR 68.1-81.3]; male 28.2%) were identified with a median follow up time of 5.3 and 6.0 years respectively. Risk of serious infection, cardiovascular disease and cancer was higher in GCA patients than in matched controls (serious infection: IRR 2.04 [95% confidence interval (CI) 1.87, 2.23]; cardiovascular disease: IRR 1.71 [95% CI 1.57, 1.88]; cancer: IRR 1.64 [95% CI 1.55, 1.74]. There was significant geographical heterogeneity in some outcomes across health boards compared to the Scottish average, particularly for cardiovascular disease in AAV (I<sup>2</sup> = 68.5%, p=0.000), and serious infection in GCA (I<sup>2</sup> = 84.9%, p=0.000), see Figure 1. <strong>Conclusions: </strong>There is geographical variation in key clinical outcomes for AAV and GCA patients across health service regions in Scotland. These findings emphasise the importance of identifying key elements of care models underpinning effective care for patients with systemic vasculitis to support regional service planning and improve outcomes. <strong>Disclosures</strong>: None <strong>Figure 1</strong>. Clinical outcomes in AAV and GCA across health service regions in Scotland