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. 2021 Sep 1;157(10):1–9. doi: 10.1001/jamadermatol.2021.2489

Table 1. Patient Characteristics by Cohort.

Characteristic No. (%)
NCDS BCS70
Total (n = 15 939)a No atopic eczema (n = 13 278 [83.3%]) Atopic eczema (n = 2661 [16.7%]) Total (n = 14 966)a No atopic eczema (n = 11 310 [75.6%]) Atopic eczema (n = 3656 [24.4%])
Asthma
No 12 633 (79.3) 10 809 (81.4) 1824 (68.5) 11 996 (80.2) 9359 (82.7) 2637 (72.1)
Any 3238 (20.3) 2402 (18.1) 836 (31.4) 2300 (15.4) 1355 (12.0) 945 (25.8)
Missing 68 (0.4) 67 (0.5) 1 (0) 670 (4.5) 596 (5.3) 74 (2.0)
Rhinitis
No 11 718 (73.5) 10 140 (76.4) 1578 (59.3) 9624 (64.3) 7836 (69.3) 1788 (48.9)
Any 4149 (26.0) 3066 (23.1) 1083 (40.7) 5329 (35.6) 3467 (30.7) 1862 (50.9)
Missing 72 (0.5) 72 (0.5) 0 (0) 13 (0.1) 7 (0.1) 6 (0.2)
Sex
Male 8200 (51.4) 6996 (52.7) 1204 (45.2) 7716 (51.6) 6110 (54.0) 1606 (43.9)
Female 7739 (48.6) 6282 (47.3) 1457 (54.8) 7250 (48.4) 5200 (46.0) 2050 (56.1)
Ethnicity
White 12 018 (75.4) 9843 (74.1) 2175 (81.7) 11 790 (78.8) 8758 (77.4) 3032 (82.9)
Other 160 (1.0) 132 (1.0) 28 (1.1) 510 (3.4) 389 (3.4) 121 (3.3)
Missing 3761 (23.6) 3303 (24.9) 458 (17.2) 2666 (17.8) 2163 (19.1) 503 (13.8)
Region of residence in childhood
Southern England 4871 (30.6) 4014 (30.2) 857 (32.2) 4427 (29.6) 3177 (28.1) 1250 (34.2)
Central England 4689 (29.4) 3866 (29.1) 823 (30.9) 3454 (23.1) 2555 (22.6) 899 (24.6)
Northern England 6379 (40.0) 5398 (40.7) 981 (36.9) 4804 (32.1) 3718 (32.9) 1086 (29.7)
Missing 0 (0) 0 (0) 0 (0) 2281 (15.3) 1860 (16.4) 421 (11.5)
Social class in childhoodb
I/II 4489 (28.2) 3632 (27.4) 857 (32.2) 5281 (35.3) 3780 (33.4) 1501 (41.1)
IIIa/b 9626 (60.4) 8069 (60.8) 1557 (58.5) 8410 (56.2) 6504 (57.5) 1906 (52.1)
IV/V 1718 (10.8) 1479 (11.1) 239 (9.0) 1238 (8.3) 995 (8.8) 243 (6.6)
Missing 106 (0.7) 98 (0.7) 8 (0.3) 37 (0.2) 31 (0.3) 6 (0.2)
Household size
≤3 Persons 1211 (7.6) 996 (7.5) 215 (8.1) 1339 (8.9) 999 (8.8) 340 (9.3)
>3 Persons 12 357 (77.5) 10 186 (76.7) 2171 (81.6) 11 374 (76.0) 8471 (74.9) 2903 (79.4)
Missing 2371 (14.9) 2096 (15.8) 275 (10.3) 2253 (15.1) 1840 (16.3) 413 (11.3)
Smoking during pregnancy
No 10 482 (65.8) 8690 (65.4) 1792 (67.3) 8050 (53.8) 5963 (52.7) 2087 (57.1)
Any 5257 (33.0) 4427 (33.3) 830 (31.2) 6847 (45.8) 5293 (46.8) 1554 (42.5)
Missing 200 (1.3) 161 (1.2) 39 (1.5) 69 (0.5) 54 (0.5) 15 (0.4)
Childhood smoke exposure
No 2993 (18.8) 2424 (18.3) 569 (21.4) 4340 (29.0) 3165 (28.0) 1175 (32.1)
Any 7953 (49.9) 6564 (49.4) 1389 (52.2) 8337 (55.7) 6272 (55.5) 2065 (56.5)
Missing 4993 (31.3) 4290 (32.3) 703 (26.4) 2289 (15.3) 1873 (16.6) 416 (11.4)
Parental history of atopy
No NA NA NA 8638 (57.7) 6687 (59.1) 1951 (53.4)
Any NA NA NA 2958 (19.8) 1918 (17.0) 1040 (28.4)
Missing NA NA NA 3370 (22.5) 2705 (23.9) 665 (18.2)
Birth weight, mean (SD), kg 3.3 (0.5) 3.3 (0.5) 3.3 (0.5) 3.3 (0.5) 3.3 (0.5) 3.3 (0.5)
Missing 529 (3.3) 445 (3.4) 84 (3.2) 14 (0.1) 13 (0.1) 1 (0.03)
Breastfeeding
No 4435 (27.8) 3742 (28.2) 693 (26.0) 7957 (53.2) 6075 (53.7) 1882 (51.5)
Any 9583 (60.1) 7832 (59.0) 1751 (65.8) 4659 (31.1) 3323 (29.4) 1336 (36.5)
Missing 1921 (12.1) 1704 (12.8) 217 (8.2) 2350 (15.7) 1912 (16.9) 438 (12.0)

Abbreviations: BCS70, 1970 British Cohort Study; NA, not applicable; NCDS, National Childhood Development Study.

a

Number is based on patients with at least 1 response to an eczema question; missing refers to number of individuals without data on each covariate.

b

Registrar General’s social class: I, professional; II, managerial and technical; III, skilled; IV, partly skilled; V, unskilled.