Table 5

Clinical details of cases and controls (early-onset cases only)

CasesControlsOdds ratio (95% CI)p Value
Sex
    Male56 (56%)123 (56%)1.05 (0.65 to 1.72)0.8
    Female4496
Apgar score at 1 min
    Median (range)8 (1 to 10)9 (3 to 10)0.68 per unit (0. 58 to 0.80)<0.001
    Percentage <733.7*10.3*
    Percentage <520.4*3.7*
Apgar score at 5 min
    Median (range)9 (3 to 10)9 (6 to 10)0.53 per unit (0.40 to 0.71)<0.001
    Percentage <711.3*0.9*
    Percentage <54.1**0**
Apgar score at 10 min
    Median (range)9 (4 to 10)10 (8 to 10)0.28 per unit (0.11 to 0.72)<0.001
    Percentage <76.40
    Percentage <54.30
Respiratory distress†
    Yes512436.77 (8.85 to 152.86)<0.001
    No49183
Oxygen required
    Yes522039.88 (9.62 to 165.33)<0.001
    No47187
Continuous positive airways pressure
    Yes23203.91 (1.75 to 8.75)<0.001
    No76187
Assisted ventilation
    Yes28849.72 (6.70 to 368.91)<0.001
    No71198
Nitric oxide
    Yes20∞ (0.00 to ∞)0.036
    No97207
Surfactant given
    Yes15722.34 (2.87 to 173.74)<0.001
    No84200
Convulsions
    Yes13213.07 (2.89 to 58.98)<0.001
    No87206
Tube feeding
    Yes40356.16 (2.90 to 13.07)<0.001
    No60183
No of days in intensive care
    Median (range)1 (0 to 21)0 (0 to 88)0.98 (0.94 to 1.03)0.3
No of days in high dependency care
    Median (range)1 (0 to 19)0 (0 to 45)1.01 (0.95 to 1.08)0.7
No of days in special care
    Median (range)7 (0 to 54)5 (0 to 59)0.97 (0.93 to 1.01)0.16
Total no of days in hospital
    Median (range)10 (1 to 71)3 (1 to 120)1.03 (1.01 to 1.06)0.004

  • Numbers do not always add up to same total due to missing data in case notes.

  • *χ2 p <0.001 cases versus controls.

  • **χ2 p = 0.003 cases versus controls.

  • †Defined as the need for supplemental oxygen for >4 h plus radiological changes.