GCA Score

Team: GCA Score, aka “GCAPS Slaps”

Base Article: Melville AR, Donaldson K, Dale J, Ciechomska A. Validation of the Southend giant cell arteritis probability score in a Scottish single-centre fast-track pathway. Rheumatol Adv Pract. 2021;6(1):rkab102. Published 2021 Dec 15. doi:10.1093/rap/rkab102

Authors: University of Chicago Fellowship Program

  1. Michael Macklin, MD, PharmD, second year rheumatology fellow, University of Chicago
  2. Chelsea Thompson, MD, second year rheumatology fellow, University of Chicago
  3. Hans Vitzthum Von Eckstaedt, MD, third year internal medicine resident, University of Chicago
  4. Asha Ailia, MD, first year rheumatology fellow, University of Chicago
  5. Ailia Ali, MD, first year rheumatology fellow, University of Chicago
  6. Kichul Ko, MD, fellowship program director, University of Chicago

Team Overview

Do giant cell arteritis (GCA) consults give you headaches? Well, the Southend Giant Cell Arteritis Probability Score (GCAPS) can help. GCAPS uses clinical and laboratory criteria to risk-stratify patients into high, medium, and low risk categories for GCA, allowing us to confidently exclude low risk patients from further invasive workup and potentially toxic trials of high-dose glucocorticoids, while giving a “full court press” of diagnostics and treatment to patients in the high-risk group.

The original GCAPS scoring system determined that patients with GCAPS ≥9.5 should trigger an “opening tip-off.” In other words, patients with GCAPS ≥9.5 require further diagnostic assessment and treatment for GCA.1 A follow-up paper broke down scores into low risk (<9), medium risk (9-12) and high risk (>12) groups, determining that no patients scoring <9 points should be considered for tip-off in the game of diagnosing GCA.2

Our chosen paper is a single center prospective study, whose results provide external validation for the GCAPS scoring system to increase your shooting percentage when it comes to correctly diagnosing GCA.3 The study found that patients with GCAPS <10 could be excluded from further diagnostic testing for GCA (100% sensitivity, 67% specificity).3 It also demonstrated that GCAPS scores ≥13 had the best overall accuracy for diagnosing GCA (93% sensitivity, 91% specificity), though we still should include patients scoring between 10-12 in our tip-off, as 7.5% of these patients were later determined to have GCA.3

Ultimately, adopting the Southend GCAPS score into clinical practice increases our shooting accuracy for diagnosing GCA.

Want to learn more?

See the Q&A on theMednet.org about the following question: How do you make the decision to empirically treat for GCA when an patient is referred but cannot be immediately seen in clinic?

Next report: LLDAS

Back to the full list of scouting reports.


  1. Laskou, Faidra et al. “A probability score to aid the diagnosis of suspected giant cell arteritis.” Clinical and experimental rheumatology vol. 37 Suppl 117,2 (2019): 104-108.
  2. Sebastian A, Tomelleri A, Kayani A, Prieto-Pena D, Ranasinghe C, Dasgupta B. Probability-based algorithm using ultrasound and additional tests for suspected GCA in a fast-track clinic. RMD Open. 2020;6(3):e001297. doi:10.1136/rmdopen-2020-001297
  3. Melville, Andrew R et al. “Validation of the Southend giant cell arteritis probability score in a Scottish single-centre fast-track pathway.” Rheumatology advances in practice vol. 6,1 rkab102. 15 Dec. 2021, doi:10.1093/rap/rkab102