Table 4:

Association of residual exclusive breastfeeding duration^¥ with prevalence of eczema (measured repeatedly at ages 1-or-2, 4, 10, and 18 years) stratified by maternal gestational smoking.

		Maternal smoking during pregnancy
Parameter	Levels	NO (k=3011)		YES (k=839)
		Risk ratio (95% CI)	p- value	Risk ratio (95% CI)	p- value
Residual duration of exclusive breastfeeding		1.00 (0.99, 1.01)	0.75	0.97 (0.94, 0.99)	0.04
	0 weeks	Ref.		Ref.
	≥ 3 weeks	1 (0.98, 1.03)	0.75	0.91 (0.84, 0.99)	0.04
	≥ 9 weeks	1.01 (0.93, 1.1)	0.75	0.76 (0.58, 0.98)	0.04
	≥ 15 weeks	1.02 (0.89, 1.2)	0.75	0.63 (0.41, 0.97)	0.04
	≥ 21 weeks	1.03 (0.85, 1.3)	0.75	0.52 (0.29, 0.96)	0.04
FLG loss of function variants		1.5 (1.06, 2.06)	0.02	1.99 (1.02, 3.90)	0.04
Time	Year 1/ 2	Ref.	Ref.	Ref.	Ref.
	Year 4	0.76 (0.63, 0.92)	0.006	0.66 (0.4, 1.08)	0.1
	Year 10	0.94 (0.78, 1.13)	0.51	0.98 (0.64, 1.48)	0.9
	Year 18	0.74 (0.60, 0.92)	0.007	0.86 (0.54, 1.39)	0.55
Weeks of gestation		1.1 (1.0, 1.23)	0.09	1.12 (0.96, 1.33)	0.15
Maternal eczema status		1.3 (0.97, 1.85)	0.07	1.17 (0.61, 2.24)	0.62
Paternal eczema status		1.87 (1.32, 2.63)	0.0004	1.24 (0.54, 2.86)	0.61
Gender (Female is the reference)	Male	0.89 (0.70, 1.14)	0.36	1.06 (0.64, 1.76)	0.81

^¥Residuals are calculated by regressing exclusive breastfeeding duration on maternal gestational smoking.

Note: Socio economic status not added in the model since it did not have enough variability in the smoking =‘Yes’ group