Table 3.
Baseline characteristics of adult cohort, aged ≥ 18 years, in The Health Improvement Network® (THIN®) database, 1994–2015
| Characteristic | Control n = 2 678 888 |
Mild AD n = 410 867 |
Moderate AD n = 196 101 |
Severe AD n = 18 115 |
|---|---|---|---|---|
| Age, median (IQR), years | 47 (32–64) | 45 (30–63) | 50 (34–68) | 47 (32–63) |
| Sex | ||||
| Female | 1 445 589 (53·96) | 256 071 (62·32) | 109 404 (55·79) | 10 736 (59·27) |
| Male | 1 233 299 (46·04) | 154 796 (37·68) | 86 697 (44·21) | 7379 (40·73) |
| Body mass index, kg m−2 | ||||
| Underweight (< 18) | 72 655 (2·71) | 11 504 (2·80) | 4150 (2·12) | 525 (2·90) |
| Normal (18·5–24·9) | 911 449 (34·02) | 152 480 (37·11) | 66 015 (33·66) | 6972 (38·49) |
| Overweight (25–29·9) | 707 292 (26·40) | 109 693 (26·70) | 56 021 (28·57) | 4799 (26·49) |
| Obese (30–34·9) | 285 567 (10·66) | 44 998 (10·95) | 24 088 (12·28) | 1900 (10·49) |
| Severely obese (35–39·9) | 94 373 (3·52) | 15 720 (3·83) | 8486 (4·33) | 653 (3·60) |
| Morbidly obese (> 40) | 44 721 (1·67) | 8341 (2·03) | 4525 (2·31) | 343 (1·89) |
| Unknown | 562 831 (21·01) | 68 131 (16·58) | 32 816 (16·73) | 2923 (16·14) |
| Smoking status | ||||
| Never | 1 293 811 (48·30) | 206 577 (50·28) | 89 588 (45·68) | 8653 (47·77) |
| Current | 576 463 (21·52) | 84 855 (20·65) | 44 195 (22·54) | 3914 (21·61) |
| Former | 548 828 (20·49) | 92 290 (22·46) | 48 636 (24·80) | 4182 (23·09) |
| Unknown | 259 786 (9·70) | 27 145 (6·61) | 13 682 (6·98) | 1366 (7·54) |
| Drinking status | ||||
| Never | 300 614 (11·22) | 51 208 (12·46) | 24 278 (12·38) | 2338 (12·91) |
| Current | 1 655 958 (61·82) | 262 008 (63·77) | 125 921 (64·21) | 11 525 (63·62) |
| Former | 114 596 (4·28) | 19 708 (4·80) | 10 187 (5·19) | 965 (5·33) |
| Unknown | 607 720 (22·69) | 77 943 (18·97) | 35 715 (18·21) | 3287 (18·15) |
| Townsend deprivation index | ||||
| 1 Lowest | 677 724 (26·39) | 102 924 (26·20) | 46 708 (24·99) | 4685 (27·26) |
| 2 Low | 564 890 (22·00) | 84 924 (21·61) | 40 579 (21·71) | 3821 (22·23) |
| 3 Moderate | 534 554 (20·82) | 81 331 (20·70) | 39255 (21·00) | 3566 (20·75) |
| 4 High | 468 773 (18·25) | 73 004 (18·58) | 35 452 (18·97) | 3038 (17·67) |
| 5 Highest | 322 027 (12·54) | 50 711 (12·91) | 24 936 (13·34) | 2079 (12·09) |
| Unknown | 110 920 (4·14) | 17 973 (4·37) | 9171 (4·68) | 926 (5·11) |
| PY per 1000, median (IQR) | 4·96 (2·09–9·18) | 4·94 (2·05–9·24) | 5·20 (2·204–9·44) | 5·41 (2·14–10·44) |
| Allergic rhinitis | 266 083 (9·93) | 66 023 (16·07) | 29 926 (15·26) | 3062 (16·90) |
| Asthma | 346 024 (12·92) | 80 267 (19·54) | 42 608 (21·73) | 4584 (25·30) |
| Congestive heart failure | 45 960 (1·72) | 7529 (1·83) | 4874 (2·49) | 369 (2·04) |
| Chronic kidney disease | 73 550 (2·75) | 10 835 (2·64) | 6903 (3·52) | 945 (5·22) |
| COPD | 62 537 (2·33) | 10 253 (2·50) | 7064 (3·60) | 591 (3·26) |
| Depression | 526 849 (19·67) | 97 510 (23·73) | 46 401 (23·66) | 4164 (22·99) |
| Diabetes mellitus | 139 798 (5·22) | 21 014 (5·11) | 12 276 (6·26) | 931 (5·14) |
| Inflammatory bowel disease | 21 204 (0·79) | 3397 (0·83) | 1852 (0·94) | 1730 (9·55) |
| Liver disease | 28 890 (1·80) | 4800 (1·17) | 2566 (1·31) | 409 (2·26) |
| Prior influenza vaccination | 411 603 (15·36) | 69 247 (16·85) | 39 315 (20·05) | 4026 (22·22) |
| Prior meningococcal vaccination | 29 938 (1·12) | 5765 (1·40) | 2468 (1·26) | 277 (1·53) |
| Prior pneumococcal vaccination | 139 513 (5·21) | 21 737 (5·29) | 12 964 (6·61) | 1262 (6·97) |
| History of herpesvirus infectiona | 315 288 (11·77) | 62 857 (15·30) | 26 864 (13·70) | 3043 (16·80) |
| History of opportunistic infectionb | 24 061 (0·90) | 4099 (1·00) | 2192 (1·12) | 248 (1·37) |
| History of serious infectionc | 67 432 (2·52) | 13 167 (3·20) | 6878 (3·51) | 944 (5·21) |
All values are n (%) unless otherwise stated. AD, atopic dermatitis; IQR, interquartile range; PY, person-years; COPD, chronic obstructive pulmonary disease.
Herpesvirus infection includes cytomegalovirus, Epstein–Barr virus, herpes simplex virus, and varicella zoster virus infections.
Opportunistic infection includes actinomycosis/nocardiosis, aspergillosis, BK virus, cryptococcosis, cytomegalovirus, mucormycosis, other mycoses (blastomycosis, coccidioidomycosis, histoplasmosis and paracoccidioidomycosis), pneumocystis, progressive multifocal leukoencephalopathy, tuberculosis and toxoplasmosis.
Serious infection includes infections of respiratory tract, urinary tract, gastrointestinal tract/abdominal cavity, bone or joints, central nervous system or meninges, heart, skin or soft tissue, prostate, breast, and eyes and sepsis requiring hospitalization.