Table 1

Comparison of background characteristics in infants with cystic fibrosis* and healthy controls

Infants with CF* (n=71)Healthy controls (n=54)Δ (95% CI), CF – controlsp Value
Boy, n (%)33 (46)27 (50)–4% (–21% to 13%)0.696
Gestational age, weeks39.3 (1.5)40.2 (1.2)–0.9 (–1.4 to –0.5)<0.001
Birth weight, z-score –0.34 (0.96)0.01 (0.84)–0.35 (–0.67 to –0.03)0.035
Birth weight below 10th percentile, n (%)16 (23)2 (4)19% (7% to 30%)0.003
White mother, n (%)62 (87)47 (87)0% (–12% to 13%)0.962
Maternal smoking during pregnancy, n (%)8 (11)4 (7)4% (–7% to 14%)0.456
Current maternal smoking, n (%)9 (13)5 (9)4% (–8% to 15%)0.540
Mother in non-manual occupation49 (69)43 (80)–11% (–25% to 5%)0.171
Fathers in non-manual occupation§ 41 (59)40 (75)–15% (–30% to 2%)0.055
Maternal asthma, n (%)13 (18)10 (19)0% (–14% to 13%)0.976
  • Data shown as n (%) for categorical variables and mean (SD) for continuous variables.

  • * Limited to those without meconium ileus.

  • Calculated using UK WHO algorithms.25

  • § n=69 CF and n=53 control infants.

  • CF, cystic fibrosis; Δ, difference between groups.