Table 1

Covariate summary statistics for individuals with and without an immune-mediated inflammatory disease (IMID)

Without IMID
n=213 512
With IMID
n=53 378
Ulcerative colitis
n=14 182
Crohn’s disease
n=9489
Psoriatic arthritis
n=6297
Rheumatoid arthritis
n=23 410
Sociodemographic characteristics
Age at study entry (years)
Mean (SD)
51.7 (17.8)51.6 (17.4)47.2 (17.0)41.8 (16.6)49.2 (13.8)59.0 (15.5)
Male sex (n (%))85 383 (40.0)21 291 (39.9)7126 (50.2)4296 (45.3)3093 (49.1)6776 (28.9)
Time since GP practice registration (years). Mean (SD)9.1 (12.1)9.1 (12.3)7.8 (11.1)7.5 (10.6)9.2 (11.6)10.4 (13.5)
Ethnicity (n (%))
 Asian9569 (5.8)2434 (5.7)724 (6.5)347 (4.7)249 ( 4.9)1114 ( 5.9)
 Black4121 (2.5)643 (1.5)127 (1.1)91 (1.2)22 ( 0.4)403 ( 2.1)
 Mixed1483 (0.9)346 (0.8)85 (0.8)67 (0.9)44 ( 0.9)150 ( 0.8)
 Other1448 (0.9)296 (0.7)93 (0.8)54 (0.7)26 ( 0.5)123 ( 0.7)
 White148 832 (90.0)38 708 (91.2)10 099 (90.8)6763 (92.4)4727 (93.3)17 119 (90.5)
 Missing48 059 (22.5)10 951 (20.5)3054 (21.5)2167 (22.8)1229 (19.5)4501 (19.2)
Index of multiple deprivation quintile (n (%))
 1 (most deprived)29 144 (13.6)7293 (13.7)1689 (11.9)1324 (14.0)803 (12.8)3477 (14.9)
 232 323 (15.1)8274 (15.5)2109 (14.9)1518 (16.0)919 (14.6)3728 (15.9)
 341 379 (19.4)10 570 (19.8)2680 (18.9)1901 (20.0)1250 (19.9)4739 (20.2)
 450 087 (23.5)12 439 (23.3)3475 (24.5)2186 (23.0)1452 (23.1)5326 (22.8)
 5 (least deprived)56 209 (26.3)13 684 (25.6)3963( 27.9)2350 (24.8)1720 (27.3)5651 (24.1)
 IMD not recorded4370 (2.0)1118 (2.1)266 (1.9)210 (2.2)153 (2.4)489 (2.1)
VTE risk factors (n (%))
 BMI (kg/m2)
 Underweight (≤18.5)4704 (2.2)1571 (2.9)368 (2.6)536 (5.6)60 ( 1.0)607 ( 2.6)
 Normal weight (18.5–25)73 675 (34.5)19 280 (36.1)5721 (40.3)4225 (44.5)1576 (25.0)7758 (33.1)
 Overweight (25–30)67 076 (31.4)16 664 (31.2)4352 (30.7)2446 (25.8)2131 (33.8)7735 (33.0)
 Obese (≥30)44 303 (20.7)11 611 (21.8)2367 (16.7)1386 (14.6)2071 (32.9)5787 (24.7)
 BMI not recorded23 754 (11.1)4252 (8.0)1374 (9.7)896 (9.4)459 ( 7.3)1523 ( 6.5)
 Smoking status
 Non-smoker94 985 (44.5)21 620 (40.5)6328 (44.6)3917 (41.3)2522 (40.1)8853 (37.8)
 Current smoker52 035 (24.4)13 070 (24.5)2574 (18.1)2914 (30.7)1519 (24.1)6063 (25.9)
 Ex-smoker63 798 (29.9)18 315 (34.3)5147 (36.3)2551 (26.9)2232 (35.4)8385 (35.8)
 Smoking status not recorded2694 (1.3)373 (0.7)133 (0.9)107 (1.1)24 ( 0.4)109 ( 0.5)
 Alcohol intake
 Non-drinker36 623 (17.2)10 608 (19.9)2371 (16.7)1798 (18.9)1035 (16.4)5404 (23.1)
 Within limits117 939 (55.2)29 316 (54.9)7727 (54.5)4917 (51.8)3508 (55.7)13 164 (56.2)
 Over recommended l imits30 096 (14.1)7145 (13.4)2083 (14.7)1228 (12.9)1067 (16.9)2767 (11.8)
 Alcoholism3438 (1.6)823 (1.5)217 (1.5)138 (1.5)128 ( 2.0)340 ( 1.5)
 Alcohol intake not recorded25 416 (11.9)5486 (10.3)1784 (12.6)1408 (14.8)559 ( 8.9)1735 ( 7.4)
Reduced mobility3562 (1.7)1022 (1.9)184 (1.3)117.2 (1.2)85 (1.3)636 (2.7)
Thrombophilia151 (0.1)49 (0.1)11 (0.1)11 (0.1)7 (0.1)20 (0.1)
Family history of VTE403 (0.2)113 (0.2)28 (0.2)27 (0.3)21 (0.3)37 (0.2)
History of fracture14 542 (6.8)3887 (7.3)978 (6.9)593 (6.2)467 (7.4)1849 (7.9)
Platelet count category (n (%))
 Low (<150×109/L)2393 (1.1)635 (1.2)141 (1.0)100 (1.1)85 (1.3)309 (1.3)
 Normal (150–400×109/L)83 707 (39.2)29 655 (55.6)7251 (51.1)4610 (48.6)3910 (62.1)13 884 (59.3)
 High (>400×109/L)3111 (1.5)4204 (7.9)908 (6.4)1158 (12.2)293 (4.7)1845 (7.9)
 Missing124 301 (58.2)18 884 (35.4)5882 (41.5)3621 (38.2)2009 (31.9)7372 (31.5)
Comorbidity (n (%))
 Hypertension43 296 (20.3)11 298 (21.2)2206 (15.2)1043 (10.7)1334 (21.2)6809 (29.1)
 Hyperlipidaemia51 377 (24.1)12 241 (22.9)2606 (18.4)1243 (13.1)1542 (24.5)6850 (29.3)
 Type 2 diabetes12 423 (5.8)3466 (6.5)714 (5.0)307 (3.2)452 (7.2)1993 (8.5)
 Peripheral vascular disease1948 (0.9)530 (1.0)98 (0.7)61 (0.6)59 (0.9)312 (1.3)
 Atrial fibrillation4569 (2.1)1227 (2.3)251 (1.8)118 (1.2)79 (1.3)779 (3.3)
 Myocardial infarction4325 (2.0)1280 (2.4)286 (2.0)125 (1.3)102 (1.6)767 (3.3)
 Stroke3344 (1.6)818 (1.5)164 (1.2)99 (1.0)66 (1.0)489 (2.1)
 Heart failure2276 (1.1)654 (1.2)129 (0.9)57 (0.6)39 (0.6)429 (1.8)
 Chronic kidney disease stages 3–56936 (3.2)1819 (3.4)294 (2.1)168 (1.8)131 (2.1)1226 (5.2)
 Chronic obstructive pulmonary disease5628 (2.6)2039 (3.8)359 (2.5)225 (2.4)130 (2.1)1325 (5.7)
 Chronic liver disease992 (0.5)559 (1.0)208 (1.5)87 (0.9)61 (1.0)203 (0.9)
 Malignancy8703 (4.1)2169 (4.1)455 (3.2)238 (2.5)211 (3.4)1265 (5.4)
Medication use (n (%))
 NSAID use49 829 (23.3)20 385 (38.2)2621 (18.5)1754 (18.5)3509 (55.7)12 501 (53.4)
 Corticosteroid use10 438 (4.9)13 166 (24.7)3283 (23.1)2734 (28.8)893 (14.2)6256 (26.7)
 Immunosuppressive medication (in primary care)1654 (0.8)18 248 (34.2)1830 (12.9)2338 (24.6)2801 (44.5)11 279 (48.2)
 Statin use29 735 (13.9)7655 (14.3)1378 (9.7)674 (7.1)839 (13.3)4764 (20.4)
 Antiplatelet therapy17 620 (8.3)4484 (8.4)871 (6.1)413 (4.4)416 (6.6)2784 (11.9)
 Warfarin2842 (1.3)760 (1.4)150 (1.1)72 (0.8)49 (0.8)489 (2.1)
 Direct oral anticoagulants939 (0.4)288 (0.5)49 (0.3)25 (0.3)21 (0.3)193 (0.8)
 Hormone replacement therapy4283 (2.0)1359 (2.5)204 (1.4)196 (2.1)206 (3.3)753 (3.2)
 Oral contraceptive use9681 (4.5)2434 (4.6)856 (6.0)817 (8.6)215 (3.4)546 (2.3)
  • BMI, body mass index; NSAID, non-steroidal anti-inflammatory drug; VTE, venous thromboembolism.