Table I.

Random-effect models and sensitivity analyses for the association between smoking and atopic dermatitis

	OR (95% CI)
Study subsets	Active smoking, n = 20	Passive smoke exposure, n = 66	Maternal smoking during pregnancy, n = 23
Overall	1.87 (1.32–2.63)	1.18 (1.01–1.38)	1.06 (0.80–1.40)
Age
Children <18 y	2.19 (1.34–3.57)	1.15 (1.01–1.30)	1.02 (0.81–1.27)
Adults ≥18 y	1.30 (1.06–1.59)	3.62 (1.71–7.69)	N/A
Study design
Case-control/cross-sectional	1.87 (1.32–2.63)	1.19 (1.01–1.41)	1.14 (0.79–1.65)
Cohort/longitudinal	N/A	1.13 (0.79–1.61)	0.93 (0.65–1.34)
Region
North America	1.66 (1.42–1.93)	1.28 (0.94–1.76)	0.49 (0.15–1.65)
South/Central America	N/A	1.95 (1.55–2.46)	N/A
Asia	1.74 (1.05–2.88)	1.22 (0.98–1.51)	1.59 (1.28–2.03)
Africa	8.41 (3.66–19.32)	2.23 (1.19–4.19)	N/A
Europe	1.91 (1.16–3.13)	0.96 (0.75–1.22)	0.94 (0.68–1.10)
Study size
<5000	2.08 (1.31–3.32)	1.30 (1.07–1.59)	1.37 (0.94–1.95)
≥5000	1.68 (1.09–2.53)	1.02 (0.81–1.29)	0.77 (0.58–0.93)
NOS score
<6	N/A	1.18 (1.11–1.26)	1.96 (1.50–2.64)
≥6	1.87 (1.32–2.63)	1.11 (0.91–1.36)	0.88 (0.67–1.16)
Amount of smoking	(n = 2)	(n = 11)	(n = 5)
Mild	2.68 (1.78–4.04)	1.21 (0.81–1.80)	1.09 (0.68–1.72)
Extensive	2.70 (1.11–6.60)	1.08 (0.74–1.59)	0.74 (0.36–1.52)

Bold indicates statistically significant associations (P < .05). Random-effect models were performed with history of atopic dermatitis as the dependent variable and active smoking, passive smoke exposure, or neonatal smoke exposure as the independent variables. Pooled OR and 95% CI were calculated. Sensitivity analyses were performed for children vs adults, North America vs South America vs Asia vs Africa vs Europe, study size <5000 vs ≥5000, Newcastle-Ottawa Scale of <6 vs ≥6, and mild vs extensive smoking.

CI, Confidence interval; N/A, not available; NOS, Newcastle-Ottawa Scale; OR, odds ratio.