TABLE 1

Characteristics of the total study population, by maternal qualifications

TotalDegree plusDiplomaA-levelsGCSE grades A–CGCSE grades D–GNonep-value#
Subjects n (%)11 141 (100)1088 (17.8)1165 (9.4)1165 (9.8)3861 (36.1)1145 (11.2)1722 (15.7)
Wheeze phenotype
 Never66.069.869.371.765.263.359.7<0.001
 Early remitting17.115.714.213.117.619.619.9
 Persistent/relapsing12.011.511.611.012.112.912.9
 Transient/intermittent4.93.04.84.25.14.37.5
Female49.149.947.349.848.448.648.60.95
Child's ethnicity
 White88.088.990.589.792.291.472.5<0.001
 Mixed3.03.72.82.72.62.73.7
 Indian1.72.41.42.40.91.22.7
 Pakistani and Bangladeshi3.81.21.23.02.32.613.1
 Black or black British2.52.53.41.31.61.95.3
 Other1.01.30.70.90.50.22.7
Maternal age years
 14–197.500.53.98.016.714.8<0.001
 20–2416.72.89.215.119.125.926.0
 25–2928.625.433.730.628.631.025.9
 30–3430.342.737.232.629.318.821.2
 35–3914.825.617.514.713.27.110.3
 ≥402.13.51.93.11.80.61.8
Maternal atopy
 None73.069.470.669.368.671.670.40.18
 Asthma or eczema23.421.425.021.624.623.922.4
 Asthma and eczema6.55.95.47.46.57.26.3
Maternal BMI
 Underweight5.53.13.03.45.38.49.9<0.001
 Normal range65.775.568.066.763.561.759.7
 Overweight20.115.520.620.521.319.522.5
 Obese6.35.05.96.37.37.25.4
 Morbidly obese2.40.92.63.02.63.22.5
Maternal smoking
 Never65.287.877.676.060.347.748.8<0.001
 Smoked before pregnancy14.79.414.614.218.417.210.5
 Smoked during pregnancy20.22.87.89.821.235.040.7
Low birthweight6.23.65.35.36.26.410.0<0.001
Caesarean section20.524.824.119.120.118.416.9<0.001
Preterm <37 weeks gestation5.84.75.43.96.55.37.10.008
Breastfeeding
 Never31.57.118.619.735.847.352.8<0.001
 ≤1 week12.18.113.011.012.616.512.1
 1–6 weeks13.110.013.914.015.413.210.7
 6 weeks–6 months19.826.924.924.919.113.211.7
 ≥6 months23.647.929.730.517.09.812.7
Exposure to smoke in same room13.12.94.46.813.223.026.2<0.001
Damp exposure13.59.89.711.413.016.020.6<0.001
“Grime” in the environment21.120.818.919.320.220.626.30.004
Furry pets37.529.838.533.041.542.035.9<0.001
Siblings in household n
 149.544.645.141.545.831.642.2
 2/351.147.251.951.353.148.651.8<0.001
 ≥46.93.33.33.86.26.417.2
Childcare
 None68.249.059.160.570.976.887.9<0.001
 Informal18.014.621.622.520.618.210.9
 Formal13.836.419.217.08.55.01.2
  • Data are presented as %, unless otherwise stated. All percentages are adjusted for sampling design and attrition. Item missingness: ethnicity 23, maternal age 7, maternal atopy 17, maternal body mass index (BMI) 657, maternal smoking 36, preterm birth 155, Caesarean section 9, environmental tobacco smoke exposure 1, damp exposure 16, grime exposure 103, furry pet exposure 1, childcare type 42. GCSE: General Certificate of Secondary Education. #: Chi-squared.