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Table 2 Parental smoking characteristics before and during pregnancy

From: Parental smoking and cessation during pregnancy and the risk of childhood asthma

     Asthma    
  Total No asthma   Prevalence    
  N (%) N (%) Asthma n (%) n/N (%) p-value aOR* 95%CI p-value**
Maternal        
Non-smokersa 28743 (73.1) 26881 (73.3) 1862 (70.5) 6.5   1 <0.001
Recent quittersb 5103 (13.0) 4755 (13.0) 348 (13.2) 6.8   1.10 (1.0-1.3) 0.218
Smokers 4748 (12.1) 4379 (11.9) 369 (14.0) 7.8 0.001 1.36 (1.2-1.6) <0.001
Missing 712 (1.8) 650 (1.8) 62 (2.3) 8.7    
Paternal        
Non-smokersa 22394 (57.0) 20921 (57.1) 1473 (55.8) 6.6   1 <0.001
Recent quttersb 4763 (12.1) 4528 (12.3) 235 (8.9) 4.9   0.31 (0.3-0.4) <0.001
Smokers 9633 (24.5) 8853 (24.1) 780 (29.5) 8.1 <0.001 2.73 (2.4-3.1) <0.001
Missing 2516 (6.4) 2363 (6.4) 153 (5.8) 6.1    
  1. aNo smoking before or during pregnancy
  2. bQuit smoking prior to or during pregnancy
  3. *Adjusted for the following maternal factors at birth: asthma, age, parity, pre-pregnancy BMI, ART, and marital status, parental smoking plus gender of child, gestational weeks at birth, mode of delivery and age at the onset of asthma, or among controls, follow-up age
  4. **p-value for adjusted analysis obtained from the trend test (Wald) in logistic regression analysis