Table 2 Associations between gender, child atopy, dampness, smoking, siblings, maternal education, parental ethnicity, and respiratory infections.

	Otitis media (n = 470)		Tonsillopharyngitis (n = 737)		Lower respiratory tract infections (n = 275)
	cOR	aOR	cOR	aOR	cOR	aOR
Gender
Male	Ref.	Ref.	Ref.	Ref.	Ref.	Ref.
Female	1.2 (1.0–1.5)	1.2 (1.0–1.5)	1.1 (1.0 –1.3)	1.2 (1.0 –1.4)	0.8 (0.6–1.1)	0.9 (0.7–1.1)
Atopy
Non‐atopic children	Ref.	Ref.	Ref.	Ref.	Ref.	Ref.
Atopic children	1.4 (1.1–1.8)	1.4 (1.1–1.8)	1.4 (1.2–1.7)	1.4 (1.1–1.7)	2.4 (1.9–3.1)	2.4 (1.8–3.1)
Home environment
No dampness	Ref.	Ref.	Ref.	Ref.	Ref.	Ref.
Home dampness	1.3 (1.0–1.6)	1.2 (1.0–1.5)	1.4 (1.2–1.7)	1.4 (1.1–1.6)	1.4 (1.1–1.8)	1.3 (1.0–1.7)
No smoking	Ref.	Ref.	Ref.	Ref.	Ref.	Ref.
Smoking by care‐giver	1.1 (0.9–1.4)	1.2 (0.9–1.5)	1.0 (0.8–1.2)	1.1 (0.9–1.3)	1.2 (0.9–1.5)	1.2 (0.9–1.6)
No siblings	Ref.	Ref.	Ref.	Ref.	Ref.	Ref.
Siblings	1.1 (0.8–1.6)	1.2 (0.8–1.6)	1.0 (0.8–1.4)	1.1 (0.8–1.4)	0.9 (0.6–1.3)	1.0 (0.6–1.4)
Maternal education
<12 years	1.2 (0.9–1.5)	1.1 (0.8–1.4)	1.1 (0.9–1.3)	0.9 (0.7–1.1)	1.0 (0.8–1.4)	0.9 (0.6–1.2)
12–15 years	1.1 (0.9–1.5)	1.1 (0.9–1.5)	1.1 (0.9–1.3)	0.9 (0.7–1.1)	1.0 (0.8–1.4)	0.9 (0.6–1.3)
<15 years	Ref.	Ref.	Ref.	Ref.	Ref.	Ref.
Parental ethnicity
Caucasian	Ref.	Ref.	Ref.	Ref.	Ref.	Ref.
African	1.4 (1.0–2.1)	1.5 (1.0–2.2)	1.7 (1.2–2.3)	1.7 (1.2–2.3)	1.7 (1.1–2.6)	1.6 (1.0–2.6)
Asian	1.2 (0.9–1.6)	1.2 (0.9–1.7)	1.5 (1.2–1.9)	1.6 (1.2–2.0)	1.2 (0.9–1.0)	1.2 (0.8–1.8)

Results expressed as crude (cOR) and adjusted odds ratios (aOR) with 95% confidence intervals in parentheses.

The risk factors gender, child atopy, dampness, smoking, siblings, maternal education, parental ethnicity, and siblings were included in multivariate logistic regression analysis in order to control for potential confounding effects.