Table 3

 Factors related to respiratory symptoms reported at both 6 and 12 months of age corrected for prematurity estimated in logistic regression analysis and modified p values allowing for multiple testing

Outcome variablePredictor variablesOdds ratioMultiple testing modified p Value*
UnadjustedAdjusted†95% CI
*Modified for multiple testing of seven outcomes using Armitage-Parmar method.4 The p values thus represent the significance for the composite hypothesis, any respiratory morbidity. Thus we interpret the findings as follows: any factor that is significant for any outcome is significantly associated with the composite outcome.5
†Adjusted adjusted for other factors in the model by logistic regression.
‡Parent reported living in rented accommodation at both time points.
§Child had an older sibling aged less than 5 at either time point.
¶Family had a cat or dog at either time point.
**Child attended a nursery at either time point.
HFOV, high frequency oscillatory ventilation; PMA, postmenstrual age.
CoughSex: boy1.801.831.11 to 3.020.053
Oxygen dependent at discharge2.011.761.00 to 3.110.12
Lives in rented accommodation‡1.961.671.02 to 2.730.14
Older siblings aged <5 years§1.702.251.34 to 3.800.006
Frequent cough, >1 per weekSex: boy2.392.621.07 to 6.420.10
Older siblings aged <5 years3.354.521.92 to 10.640.003
Cough without infectionOxygen dependent at discharge2.422.871.19 to 6.920.056
Lives in rented accommodation2.962.391.03 to 5.540.12
Older siblings aged <5 years3.233.691.59 to 8.550.006
WheezeMultiple birth0.360.370.18 to 0.770.024
Oxygen dependent at 36 wks PMA2.432.741.55 to 4.830.003
Pet ownership¶0.420.430.21 to 0.870.059
Older siblings aged <5 years1.541.981.13 to 3.490.053
Frequent wheeze, >1 per weekSex: boy13.9813.561.76 to 104.710.036
Wheeze without infectionSex: boy2.462.681.11 to 6.450.082
Lives in rented accommodation3.462.781.20 to 6.430.051
Chest medicineRandomised mode of ventilation at birth: HFOV0.560.540.30 to 0.990.13
Bronchodilators, inhaled/oral steroidsSex: boy2.732.451.32 to 4.540.015
Multiple birth0.480.380.17 to 0.850.053
Oxygen dependent at 36 weeks PMA3.702.361.13 to 4.930.065
Oxygen dependent at discharge4.182.081.04 to 4.14
At nursery**0.370.300.10 to 0.930.11