Table 1. Characteristics of the 68 Included Studies.
| Characteristic | No. (%)a | |
|---|---|---|
| Studies (n = 68) | Patients (n = 14 037)b | |
| Year of publication | ||
| Before 1990 | 9 (13.2) | 797 (5.7) |
| 1990-1999 | 6 (8.8) | 1235 (8.8) |
| 2000-2009 | 13 (19.1) | 2119 (15.1) |
| 2010-2019 | 40 (58.8) | 9886 (70.4) |
| Study design | ||
| Prospective cohort | 20 (29.4) | 2104 (15.0) |
| Retrospective cohort | 48 (70.6) | 11 933 (85.0) |
| Setting of care | ||
| Nonacademic center | 7 (10.3) | 664 (4.7) |
| Academic center | 56 (82.4) | 7777 (55.4) |
| Nonacademic/academic center | 4 (5.9) | 3155 (22.5) |
| Unclear | 1 (1.5) | 2441 (17.4) |
| Identification of patients | ||
| Central pathology/surgery registry | 28 (41.2) | 10 337 (73.6) |
| Central imaging registry | 7 (10.3) | 412 (2.9) |
| Central pathology/surgery and central imaging registry | 2 (2.9) | 55 (0.4) |
| Ophthalmology department | 14 (20.6) | 1452 (10.3) |
| Rheumatology department | 7 (10.3) | 709 (5.1) |
| Multiple hospital departments | 9 (13.2) | 1006 (7.2) |
| Unclear | 1 (1.5) | 66 (0.5) |
| Specialty referring patients | ||
| Primary care | 1 (1.5) | 125 (0.9) |
| Hospital departments | 3 (4.4) | 481 (3.4) |
| Primary care and hospital departments | 8 (11.8) | 2701 (19.2) |
| Unclear | 56 (82.4) | 10 730 (76.4) |
| Laboratory results before treatment | ||
| No | 8 (11.8) | 2779 (19.8) |
| Yes | 6 (8.8) | 800 (5.7) |
| Unclear | 27 (39.7) | 5824 (41.5) |
| Not applicable | 27 (39.7) | 4634 (33.0) |
| Type of reference standard | ||
| TAB | 38 (55.9) | 11 207 (79.8) |
| Clinical diagnosisc | 30 (44.1) | 2830 (20.2) |
| Focus of diagnostic testing | ||
| Cranial arteries | 53 (77.9) | 12 543 (89.4) |
| Systemic arteries | 1 (1.5) | 63 (0.4) |
| Cranial and systemic arteries | 14 (20.6) | 1431 (10.2) |
Abbreviations: GCA, giant cell arteritis; TAB, temporal artery biopsy.
a
Percentages have been rounded and may not total 100.
b
A total of 4277 patients were classified as having GCA.
c
Seven studies with the clinical diagnosis as the reference standard46,68,71,75,76,77,82 also allowed evaluation of TAB as the reference standard (558 patients). One study with the clinical diagnosis as the reference standard68 also allowed evaluation of ultrasonography as the reference standard (23 patients).