|
Explanatory variable
|
Umtata
|
Cape Town
|
|---|
|
Total, n (%)
|
Case, n (%)
|
Control, n (%)
|
p-value
|
Total, n (%)
|
Case, n (%)
|
Control, n (%)
|
p-value
|
|---|
|
Total
|
111 (100)
|
58 (52)
|
53 (48)
|
0.502a
|
74 (100)
|
43 (58)
|
31 (42)
|
0.049a
|
|
Age (months)
|
|
Mean [standard deviation]
|
21.27 [7.15]
|
21.03 [7.41]
|
21.53 [6.90]
|
0.718
|
24.19 [7.37]
|
23.98 [7.44]
|
24.48 [7.38]
|
0.773
|
|
Sex
|
|
Female
|
42 (39)
|
24 (43)
|
18 (34)
|
0.431
|
36 (49)
|
19 (44)
|
17 (55)
|
0.480
|
|
Male
|
67 (61)
|
32 (57)
|
35 (66)
|
38 (51)
|
24 (56)
|
14 (45)
|
|
AD severity
|
|
Moderate
|
23 (40)
|
23 (40)
|
–
| |
21 (49)
|
21 (49)
|
–
| |
|
Severe
|
35 (60)
|
35 (60)
|
–
| |
22 (51)
|
22 (51)
|
–
| |
|
Atopic disease
|
|
Food allergy
|
11 (10)
|
10 (17)
|
1 (2)
|
0.009
|
9 (12)
|
9 (21)
|
0 (0)
|
0.008
|
|
Asthma
|
0 (0)
|
0 (0)
|
0 (0)
| |
1 (1)
|
1 (3)
|
0 (0)
|
1.000
|
|
Allergic rhinitis
|
7 (8)
|
1 (2)
|
6 (11)
|
0.242
|
1 (1)
|
1 (3)
|
0 (0)
|
1.000
|
|
Mode of birth
|
|
Caesarean section
|
25 (23)
|
14 (24)
|
11 (21)
|
0.821
|
33 (46)
|
20 (49)
|
13 (42)
|
0.637
|
|
Vaginal
|
86 (77)
|
44 (76)
|
42 (79)
|
39 (54)
|
21 (51)
|
18 (58)
|
|
Breastfeeding
|
35 (32)
|
10 (17)
|
25 (47)
|
0.001
|
9 (12)
|
7 (16)
|
2 (6)
|
0.288
|
|
Antibiotic exposure
|
92 (82)
|
49 (83)
|
43 (81)
|
0.810
|
54 (72)
|
30 (70)
|
24 (77)
|
0.598
|
|
Immunisation status
|
|
Complete
|
107 (96)
|
56 (95)
|
52 (98)
|
0.620
|
64 (86)
|
33 (77)
|
31 (100)
|
0.004
|
|
Incomplete
|
4 (4)
|
3 (5)
|
1 (2)
|
10 (14)
|
10 (23)
|
0 (0)
|
|
Large family a
|
62 (55)
|
30 (52)
|
32 (60)
|
0.445
|
24 (32)
|
14 (33)
|
10 (32)
|
1.000
|
|
Animal exposure
|
93 (84)
|
39 (67)
|
53 (100)
|
0.001
|
2 (3)
|
2 (6)
|
0 (0)
|
0.495
|
|
Parental education
|
|
Primary
|
8 (7)
|
2 (3)
|
6 (11)
|
0.001
|
1 (1)
|
1 (2)
|
0 (0)
|
0.025
|
|
Secondary
|
70 (63)
|
31 (53)
|
39 (74)
|
33 (45)
|
14 (33)
|
19 (61)
|
|
Tertiary
|
31 (28)
|
25 (43)
|
6 (11)
|
40 (54)
|
28 (65)
|
12 (39)
|
|
Other
|
2 (2)
|
0 (0)
|
2 (4)
|
0 (0)
|
0 (0)
|
0 (0)
|
|
Maternal factors
|
|
Animal exposure
|
96 (86)
|
44 (76)
|
52 (98)
|
0.001
|
4 (60)
|
4 (11)
|
0 (0)
|
0.120
|
|
Pregnant smoking
|
1 (1)
|
0 (0)
|
1 (2)
|
0.482
|
3 (45)
|
0 (0)
|
3 (10)
|
0.094
|
|
Smoking
|
1 (1)
|
0 (0)
|
1 (2)
|
0.477
|
4 (6)
|
1 (3)
|
3 (10)
|
0.324
|
|
Asthma
|
2 (2)
|
2 (3)
|
0 (0)
|
0.496
|
6 (8)
|
4 (10)
|
2 (6)
|
1.000
|
|
Allergic rhinitis
|
4 (4)
|
4 (7)
|
0 (0)
|
0.120
|
5 (68)
|
4 (10)
|
1 (3)
|
0.387
|
|
Atopic dermatitis
|
2 (2)
|
2 (3)
|
0 (0)
|
0.496
|
3 (4)
|
2 (5)
|
1 (3)
|
1.000
|
|
Food allergy
|
3 (3)
|
2 (3)
|
1 (2)
|
1.000
|
1 (1)
|
1 (2)
|
0 (0)
|
1.000
|
|
Paternal factors
|
|
Smoking
|
15 (14)
|
9 (16)
|
6 (12)
|
0.589
|
20 (31)
|
11 (31)
|
9 (31)
|
1.000
|
|
Asthma
|
3 (3)
|
3 (5)
|
0 (0)
|
0.245
|
0 (0)
|
0 (0)
|
0 (0)
| |
|
Allergic rhinitis
|
3 (3)
|
3 (5)
|
0 (0)
|
0.245
|
7 (10)
|
7 (17)
|
0 (0)
|
0.018
|
|
Atopic dermatitis
|
1 (1)
|
1 (2)
|
0 (0)
|
1.000
|
2 (3)
|
2 (5)
|
0 (0)
|
0.505
|
|
Food allergy
|
1 (1)
|
1 (2)
|
0 (0)
|
1.000
|
1 (1)
|
1 (2)
|
0 (0)
|
1.000
|
|
Household factors
|
|
Electricity + gas
|
69 (62)
|
56 (97)
|
13 (25)
|
0.001
|
66 (99)
|
35 (97)
|
31 (100)
|
1.000
|
|
Kerosene + paraffin
|
64 (58)
|
44 (76)
|
20 (38)
|
0.001
|
43 (64)
|
21 (58)
|
22 (71)
|
0.317
|
|
Paraffin
|
38 (34)
|
6 (10)
|
32 (60)
|
0.001
|
0 (0)
|
0 (0)
|
0 (0)
| |
|
Indoor fire
|
4 (4)
|
2 (3)
|
2 (4)
|
1.000
|
0 (0)
|
0 (0)
|
0 (0)
| |
|
Outdoor fire
|
49 (44)
|
12 (21)
|
37 (70)
|
0.001
|
0 (0)
|
0 (0)
|
0 (0)
| |
|
Wood + fire
|
31 (28)
|
4 (7)
|
27 (51)
|
0.001
|
0 (0)
|
0 (0)
|
0 (0)
| |
- Bold text indicates statistical significance. AD atopic dermatitis, CI confidence interval, IQR interquartile range; a Large family is arbitrarily defined as 7 or more members living within one household
