Table 4 Odds ratios (95% confidence intervals) for respiratory symptoms, hay fever and eczema, determined by multiple regression analysis. Significant relations are printed in bold. Birth weight, gestational age, duration of mechanical ventilation and smoking habits are entered as categorical covariates.

birth weight (gram)

500–1000

0.4 (0.2–1.1)

0.6 (0.2–2.4)

1.6 (0.7–4.0)

0.6 (0.2–1.9)

1.2 (0.3–4.4)

1.2 (0.3–4.5)

1000–1500

0.5 (0.3–1.2)

0.8 (0.3–2.0)

1.7 (0.8–3.6)

1.0 (0.4–2.3)

1.4 (0.5–3.6)

1.5 (0.6–4.3)

Gestational age (weeks)

till 28

0.4 (0.2–0.9) †

0.8 (0.2–2.6)

0.9 (0.4–1.9)

1.1 (0.5–2.7)

1.3 (0.4–4.2)

0.9 (0.3–2.7)

28–31

0.5 (0.2–0.9) †

1.1 (0.4–2.6)

1.0 (0.6–1.9)

0.7 (0.3–1.4)

1.2 (0.5–2.9)

0.9 (0.4–2.3)

Mechanical ventilation (days)

1–7 days

1.1 (0.6–216)

1.3 (0.6–3.1)

1.0 (0.5–1.9)

1.1 (0.5–2.2)

1.4 (0.6–3.2)

1.21 (0.5–2.8)

8–28 days

0.9 (0.4–2.2)

0.3 (0.1–1.5)

1.2 (0.6–2.6)

0.7 (0.3–1.9)

0.7 (0.2–2.3)

1.1 (0.4–3.4)

>28

5.2 (1.2–23.3) †

0.3 (0.0–4.0)

1.6 (0.4–6.9)

0.2 (0.2–2.7)

0.7 (0.1–7.7)

0.4 (0.0–3.7)

female gender

1.6 (1.0–2.7)

1.2 (0.6–2.3)

2.0 (1.2–3.2) †

3.8 (2.0–7.3) ‡

0.7 (0.1–7.7)

1.3 (0.7–2.5)

Maternal smoking

1.1 (0.6–1.9)

1.6 (0.7–3.5)

1.6 (1.0–2.8)

1.3 (0.7–2.5)

0.6 (0.3–1.3)

1.0 (0.5–2.1)

Maternal asthma

2.5 (1.2–5.4) †

4.2 (1.8–10.5) ‡

1.3 (0.6–2.9)

1.6 (0.6–4.1)

1.8 (0.6–5.2)

2.0 (0.7–5.3)

BPD

3.1 (1.2–8.2) †

3.1 (0.7–14.6)

1.5 (0.6–3.6)

2.0 (0.6–6.9)

0.4 (0.1–2.3)

2.4 (0.8–7.4)

Smoking participant

past

1.2 (0.6–2.5)

0.6 (0.2–1.7)

0.9 (0.4–1.9)

2.2 (1.0–4.8) †

1.5 (0.6–3.6)

1.4 (0.6–3.4)

"party"

0.5 (0.1–1.5)

0.9 (0.3–2.9)

1.9 (0.8–4.0)

0.9 (0.3–2.5)

0.3 (0.0–2.3)

1.3 (0.5–3.8)

daily

2.7 (1.5–5.1) ‡

0.4 (0.1–1.1)

2.6 (1.5–4.6) ‡

1.5 (0.7–2.9)

1.6 (0.7–3.7)

1.0 (0.4–2.5)