TABLE 2

Prevalence of wheeze patterns by covariates and univariate relative risk ratios (RRRs) for wheeze patterns for each covariate

NeverEarly remittingPersistent/relapsing
%RRR (95% CI)%RRR (95% CI)%RRR (95% CI)
Total6617.112.0
Maternal qualifications
 Degree plus69.8115.71.00 (1.00–1.00)11.51.00 (1.00–1.00)
 Diploma69.3114.20.91 (0.72–1.15)11.61.02 (0.77–1.35)
 A-levels71.7113.10.81 (0.66–1.00)110.93 (0.72–1.20)
 GCSE grades A–C65.2117.61.20 (1.02–1.41)12.11.12 (0.92–1.37)
 GCSE grades D–G63.3119.61.37 (1.10–1.71)12.91.24 (0.94–1.63)
 None59.7119.91.48 (1.22–1.80)12.91.31 (1.04–1.65)
Demographic factors
 Male62.9117.61.00 (1.00–1.00)14.21.00 (1.00–1.00)
 Female69.6116.40.84 (0.75–0.94)9.70.61 (0.53–0.71)
Ethnicity
 White66.1117.11.00 (1.00–1.00)121.00 (1.00–1.00)
 Mixed63.3118.71.14 (0.80–1.63)11.91.03 (0.72–1.49)
 Indian69.4112.40.69 (0.45–1.06)13.11.04 (0.62–1.73)
 Pakistani and Bangladeshi66.6114.40.84 (0.68–1.03)12.81.06 (0.79–1.41)
 Black or black British62.9121.11.30 (0.92–1.84)10.50.92 (0.61–1.38)
 Other78190.45 (0.28–0.72)8.60.60 (0.32–1.14)
Maternal age years
 14–1960.7122.91.82 (1.40–2.37)10.70.90 (0.65–1.25)
 20–2463.2119.41.48 (1.21–1.81)12.10.98 (0.77–1.25)
 25–2966.1117.11.25 (1.03–1.50)11.80.91 (0.74–1.13)
 30–3468.6115.21.07 (0.90–1.28)11.90.89 (0.74–1.07)
 35–3967.9114.11.00 (1.00–1.00)13.31.00 (1.00–1.00)
 ≥4062.5120.71.60 (1.12–2.28)10.90.89 (0.57–1.41)
Maternal atopy
 No risk69.5115.61.00 (1.00–1.00)10.11.00 (1.00–1.00)
 Asthma or eczema/hayfever59.7119.71.47 (1.28–1.67)15.41.76 (1.53–2.03)
 Asthma and eczema/hayfever52.9121.91.84 (1.46–2.33)19.82.57 (2.03–3.25)
Maternal BMI
 Underweight65119.91.26 (0.95–1.67)11.91.10 (0.79–1.52)
 Normal range67.4116.41.00 (1.00–1.00)11.21.00 (1.00–1.00)
 Overweight63.9117.51.13 (0.97–1.31)13.31.25 (1.05–1.48)
 Obese63.6118.41.19 (0.97–1.47)14.61.38 (1.06–1.80)
 Morbidly obese57.6122.21.58 (1.10–2.29)15.11.57 (1.01–2.45)
Maternal smoking
 Never69.4115.11.00 (1.00–1.00)11.21.00 (1.00–1.00)
 Smoked before pregnancy62.7118.61.36 (1.16–1.61)12.81.26 (1.06–1.50)
 Smoked during pregnancy58.3122.21.75 (1.51–2.03)13.61.44 (1.23–1.69)
Cigarettes smoked during  pregnancy cigarettes·day-1
 068.2115.71.00 (1.00–1.00)11.51.00 (1.00–1.00)
 1–961.5121.11.49 (1.23–1.80)11.81.13 (0.91–1.41)
 10–1957.9121.71.63 (1.33–1.99)14.71.50 (1.17–1.93)
 ≥2054.5121.81.74 (1.24–2.42)16.31.77 (1.26–2.48)
Perinatal factors
 Low birthweight#59.2119.51.30 (1.03–1.65)16.41.58 (1.18–2.10)
 Caesarean section#63.6117.31.08 (0.94–1.25)141.29 (1.08–1.53)
 Preterm <37 weeks gestation#54.2122.31.64 (1.29–2.09)16.91.77 (1.34–2.35)
Breastfeeding
 Never61.8119.71.00 (1.00–1.00)13.21.00 (1.00–1.00)
 ≤1 week64.5118.20.88 (0.73–1.08)12.30.89 (0.72–1.11)
 1–6 weeks66.9116.50.88 (0.73–1.07)11.30.97 (0.78–1.20)
 6 weeks–6 months71113.80.71 (0.60–0.84)11.30.72 (0.59–0.87)
Postnatal exposures
 Environmental tobacco smoke#62.3119.51.26 (1.07–1.48)131.17 (0.96–1.44)
 Damp#62.6119.11.22 (1.02–1.46)12.51.12 (0.93–1.35)
 Grime#63.3118.51.19 (1.03–1.37)12.81.15 (0.99–1.33)
 Pets#66.3116.90.99 (0.89–1.11)11.30.90 (0.79–1.04)
 Siblings in household n
  166.5116.41.00 (1.00–1.00)11.91.00 (1.00–1.00)
  2/365.8117.91.10 (0.98–1.24)11.81.00 (0.89–1.12)
  ≥466.5113.90.85 (0.66–1.09)14.41.21 (0.93–1.56)
 Childcare
  No65.8116.51.00 (1.00–1.00)5.31.00 (1.00–1.00)
  Informal66.3117.71.06 (0.91–1.24)4.40.94 (0.79–1.12)
  Formal67.6118.31.08 (0.93–1.24)3.50.84 (0.68–1.04)
  • Data are presented as % or RRR (95% CI). n=11 141. GCSE: General Certificate of Secondary Education; BMI: body mass index. #: reference group for binary variables not shown; reference not low birthweight/Caesarean section/preterm birth.