The one-year infection risk among patients diagnosed with giant cell arteritis: use of antibiotics and hospitalisations

Philip Therkildsen; Annette de Thurah; Berit Dalsgaard Nielsen; Mikkel Faurschou; Bo Baslund; Ib Tønder Hansen; Mette Nørgaard; Ellen Margrethe Hauge

doi:10.1093/rheumatology/keae107

The one-year infection risk among patients diagnosed with giant cell arteritis: use of antibiotics and hospitalisations

Rheumatology (Oxford). 2024 Feb 10:keae107. doi: 10.1093/rheumatology/keae107. Online ahead of print.

Authors

Philip Therkildsen¹, Annette de Thurah^{1

2}, Berit Dalsgaard Nielsen^{1

2

3}, Mikkel Faurschou⁴, Bo Baslund⁴, Ib Tønder Hansen^{1

2}, Mette Nørgaard^{2

5}, Ellen Margrethe Hauge^{1

2}

Affiliations

¹ Department of Rheumatology, Aarhus University Hospital, Aarhus, Denmark.
² Department of Clinical Medicine, Aarhus University, Aarhus, Denmark.
³ Department of Internal Medicine, Horsens Regional Hospital, Horsens, Denmark.
⁴ Copenhagen Lupus and Vasculitis Clinic, COPEACT, Center for Rheumatology and Spine Diseases, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark.
⁵ Department of Clinical Epidemiology, Aarhus University Hospital, Aarhus, Denmark.

PMID: 38341668
DOI: 10.1093/rheumatology/keae107

Abstract

Objectives: Patients with giant cell arteritis (GCA) primarily have their infections managed by primary care providers and hospitalisation is rarely necessary. Existing studies in GCA focus on infection-related hospitalisations only, whereas the use of antibiotic prescriptions is largely unknown. This study aims to examine the one-year overall infection risk among patients with GCA.

Methods: This nationwide observational cohort study included patients aged ≥50 years with a first-time GCA diagnosis in the Danish National Patient Registry (1996-2022). Patients with GCA were matched 1:10 by sex and date of birth with general population individuals and followed from date of diagnosis. Overall infections were defined as redeemed antibiotic prescriptions or infection-related hospitalisations. Utilising a pseudo-observation approach, we assessed 1-year cumulative incidence proportions (CIP), risk differences (RD), and relative risks (RR) of infections.

Results: The study included 17 773 incident patients with GCA and 177 730 reference individuals. Patients with GCA had a 1-year CIP of 52.4% (95% CI: 51.7-53.2) for overall infections and 17.6% (95% CI: 17.1-18.2) for infection-related hospitalisations. Compared with the reference cohort, patients with GCA had a RR of 1.40 (95% CI: 1.38-1.42) for overall infections and 2.71 (95% CI: 2.61-2.82) for infection-related hospitalisations. Additionally, higher cumulative glucocorticoid doses, advanced age (≥70 years), and higher comorbidity were associated with an increased risk of infections among patients with GCA.

Conclusions: The use of antibiotic prescriptions and infection-related hospitalisations in the first year after a GCA diagnosis is high compared with the background population. The cumulative glucocorticoid dose is associated with the infection risk.

Keywords: Antibiotics; Epidemiology; Giant cell arteritis; Glucocorticoids; Infections.