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.