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 variable | Predictor variables | Odds ratio | Multiple testing modified p Value* | ||
|---|---|---|---|---|---|
| Unadjusted | Adjusted† | 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. | |||||
| Cough | Sex: boy | 1.80 | 1.83 | 1.11 to 3.02 | 0.053 |
| Oxygen dependent at discharge | 2.01 | 1.76 | 1.00 to 3.11 | 0.12 | |
| Lives in rented accommodation‡ | 1.96 | 1.67 | 1.02 to 2.73 | 0.14 | |
| Older siblings aged <5 years§ | 1.70 | 2.25 | 1.34 to 3.80 | 0.006 | |
| Frequent cough, >1 per week | Sex: boy | 2.39 | 2.62 | 1.07 to 6.42 | 0.10 |
| Older siblings aged <5 years | 3.35 | 4.52 | 1.92 to 10.64 | 0.003 | |
| Cough without infection | Oxygen dependent at discharge | 2.42 | 2.87 | 1.19 to 6.92 | 0.056 |
| Lives in rented accommodation | 2.96 | 2.39 | 1.03 to 5.54 | 0.12 | |
| Older siblings aged <5 years | 3.23 | 3.69 | 1.59 to 8.55 | 0.006 | |
| Wheeze | Multiple birth | 0.36 | 0.37 | 0.18 to 0.77 | 0.024 |
| Oxygen dependent at 36 wks PMA | 2.43 | 2.74 | 1.55 to 4.83 | 0.003 | |
| Pet ownership¶ | 0.42 | 0.43 | 0.21 to 0.87 | 0.059 | |
| Older siblings aged <5 years | 1.54 | 1.98 | 1.13 to 3.49 | 0.053 | |
| Frequent wheeze, >1 per week | Sex: boy | 13.98 | 13.56 | 1.76 to 104.71 | 0.036 |
| Wheeze without infection | Sex: boy | 2.46 | 2.68 | 1.11 to 6.45 | 0.082 |
| Lives in rented accommodation | 3.46 | 2.78 | 1.20 to 6.43 | 0.051 | |
| Chest medicine | Randomised mode of ventilation at birth: HFOV | 0.56 | 0.54 | 0.30 to 0.99 | 0.13 |
| Bronchodilators, inhaled/oral steroids | Sex: boy | 2.73 | 2.45 | 1.32 to 4.54 | 0.015 |
| Multiple birth | 0.48 | 0.38 | 0.17 to 0.85 | 0.053 | |
| Oxygen dependent at 36 weeks PMA | 3.70 | 2.36 | 1.13 to 4.93 | 0.065 | |
| Oxygen dependent at discharge | 4.18 | 2.08 | 1.04 to 4.14 | ||
| At nursery** | 0.37 | 0.30 | 0.10 to 0.93 | 0.11 | |
