Session Information
Date: Sunday, October 21, 2018
Title: Vasculitis Poster I: Non-ANCA-Associated and Related Disorders
Session Type: ACR Poster Session A
Session Time: 9:00AM-11:00AM
Background/Purpose: To investigate the incidence rate and seasonal variation of biopsy-proven giant cell arteritis (GCA) in a well-defined population in southern Sweden.
Methods: The study area was the County of Skåne with a total population of 1,324,565 as of December 2016 (37% aged ≥50 years). Patients who underwent temporal artery biopsy (TAB) between 1997 and 2016 and lived in Skåne at time of TAB were identified using the database at the Departments of Pathology serving Skåne. All pathology reports of all TABs performed in the region during the 20-year period were retrieved and reviewed. Only patients with TAB positive GCA were included. The study period was divided into 4 five-year periods to study possible fluctuation of the incidence over time. Date of TAB was used to study possible seasonal variations in the incidence of TAB+GCA. The seasons were defined as follow: winter (December-February), spring (March-May), summer (June-August) and autumn (September-November). Incidence rates per 100,000 persons aged ≥50 years are presented.
Results: A total of 5886 TABs were identified during the study time. Of these, 1202 patients (864 females, 72%) were found to have a positive TAB during the 20-year period. The mean age at diagnosis was 75.1 years (SD 8.0) for all patients, 75.4 years (SD 7.8) for women and 74.5 years (SD 8.5) for men. The annual incidence rate of biopsy-proven GCA per 100000 persons in the age group ≥50 years was estimated to 13.7 (95% CI 12.9-14.4) and was higher among women (18.4 vs. 8.2 for men, p=0.04). There was a decline in the incidence rate over time: 15.8 during period 1 (1997-2001) vs. 12.2 in period 4 (2012-2016), p<0.01 (Table 1). The incidence rate of performed TABs declined during the study period, 76.4 (95% CI 72.6-80.6) during period 1 vs. 58.4 (95% CI 55.4-61.5) during period 4, p<0.01. There was a seasonal variation in the diagnosis of GCA, with more patients diagnosed during spring and summer compared to autumn and winter (331 patients diagnosed during spring, 319 during summer, 282 during autumn and 270 during winter, p=0.04).
Conclusion: The incidence rate of biopsy-proven GCA decreased over time. Similarly, the number of performed TABs decreased during the study period. A possible explanation for this may be an increased use of imaging studies in diagnosing GCA. We also observed a seasonal variation, with more patients diagnosed during spring and summer, possibly due to season related exposures, e.g. infections.
|
All |
95% CI |
Men |
95% CI |
Women |
95% CI |
|
|
Period 1 (1997–2001) |
15.8 |
14.1 – 17.6 |
7.9 |
6.1 – 9.7 |
15.8 |
14.1 – 17.6 |
|
Period 2 (2002–2006) |
13.2 |
11.6 – 14.7 |
8,0 |
6.3 – 9.8 |
17.6 |
15.2 – 20.1 |
|
Period 3 (2007–2011) |
13.6 |
12 – 15.1 |
7.4 |
5.8 – 9.1 |
19,0 |
16.5 – 21.5 |
|
Period 4 (2012–2016) |
12.2 |
10.8 – 13.6 |
9.2 |
7.5 – 11 |
15,0 |
12.8 – 17.1 |
|
1997-2016 |
13.7 |
12.9 – 14.4 |
8.2 |
7.3 – 9 |
18.4 |
17.2 – 19.7 |
To cite this abstract in AMA style:
Stamatis P, Turesson C, Nilsson JÅ, Mohammad A. Incidence And Seasonal Variation Of Biopsy-Proven Giant Cell Arteritis – Revisited: A 20-Year Population-Based Study From Sweden [abstract]. Arthritis Rheumatol. 2018; 70 (suppl 9). https://acrabstracts.org/abstract/incidence-and-seasonal-variation-of-biopsy-proven-giant-cell-arteritis-revisited-a-20-year-population-based-study-from-sweden/. Accessed .ACR Meeting Abstracts - https://acrabstracts.org/abstract/incidence-and-seasonal-variation-of-biopsy-proven-giant-cell-arteritis-revisited-a-20-year-population-based-study-from-sweden/