Table 1.
Baseline characteristics of cohort 1 (UKIVAS)
| Characteristics | Total | GPA | MPA | EGPA | p |
|---|---|---|---|---|---|
| n (%) | 1961 | 1124 (57.3) | 600 (30.6) | 237 (12.1) | |
| Age (years, median [IQR]) | 60 [49, 69] | 58 [47, 67] | 66 [57, 73] | 57 [47, 65] | < 0.001 |
| Male (%) | 1017 (51.9) | 610 (54.3) | 280 (46.7) | 127 (53.6) | 0.009 |
| Ethnicity (%) | < 0.001 | ||||
| White | 1796 (91.6) | 1049 (93.3) | 534 (89.0) | 213 (89.9) | |
| Asian | 85 (4.3) | 44 (3.9) | 34 (5.7) | 7 (3.0) | |
| Black | 29 (1.5) | 4 (0.4) | 16 (2.7) | 9 (3.8) | |
| Mixed | 9 (0.5) | 5 (0.4) | 3 (0.5) | 1 (0.4) | |
| Others | 42 (2.1) | 22 (2.0) | 13 (2.2) | 7 (3.0) | |
| ANCA subtype (ELISA) (%) | < 0.001 | ||||
| PR3 | 499 (25.4) | 437 (38.9) | 53 (8.8) | 9 (3.8) | |
| MPO | 340 (17.3) | 52 (4.6) | 240 (40.0) | 48 (20.3) | |
| ELISA-negative | 63 (3.2) | 21 (1.9) | 15 (2.5) | 27 (11.4) | |
| Others | 6 (0.3) | 3 (0.3) | 2 (0.3) | 1 (0.4) | |
| No ELISA recorded | 1053 (53.7) | 611 (54.4) | 290 (48.3) | 152 (64.1) | |
| Latitude (degrees, median [IQR]) | 52.24 [51.50, 53.38] | 52.40 [51.54, 53.42] | 51.82 [51.46, 52.94] | 52.24 [51.44, 53.48] | < 0.001 |
| Longitude (degrees, median [IQR]) | − 1.20 [− 2.23, − 0.14] | − 1.48 [− 2.36, − 0.20] | − 0.57 [− 2.00, − 0.10] | − 1.38 [− 2.20, − 0.18] | < 0.001 |
| CW-D-UVB at symptom onset (kJ/m2, median [IQR]) | 83.82 [25.30, 168.57] | 80.72 [25.03, 167.62] | 88.40 [26.50, 167.44] | 82.51 [24.50, 172.69] | 0.914 |
| Season of diagnosis (%) | 0.891 | ||||
| Spring | 490 (25.0) | 285 (25.4) | 143 (23.8) | 62 (26.2) | |
| Summer | 527 (26.9) | 307 (27.3) | 161 (26.8) | 59 (24.9) | |
| Autumn | 480 (24.5) | 274 (24.4) | 144 (24.0) | 62 (26.2) | |
| Winter | 464 (23.7) | 258 (23.0) | 152 (25.3) | 54 (22.8) |
Continuous variables are reported as mean (standard deviation (SD)) or median (interquartile range (IQR)) if not normally distributed and compared using the independent sample t-test or the Mann-Whitney U test, respectively. Categorical variables are summarised by frequency and percentage (%) and compared using the χ2 test
Refer to supplementary materials for definitions of ‘date of symptom onset’ and seasons
ANCA anti-neutrophil cytoplasmic antibodies, ELISA enzyme-linked immunoassay, PR3 proteinase-3, MPO myeloperoxidase, CW-DUVB cumulative-weighted UVB dose, SD standard deviation, IQR inter-quartile range