Table 4

Multivariable main associations between increasing childhood bronchitis severity by age 7 and various lung conditions at age 53 years

Lung condition at age 53Cases (N)Model NChildhood bronchitis severity at age 7 (N=3202)†‡
Non-recurrent (n=902)Recurrent, non-protracted (n=578)Recurrent-protracted (n=42)
Case (n)OR (95% CI)Case (n)OR (95% CI)Case (n)OR (95% CI)
CB-current1583062400.90 (0.67 to 1.22)321.07 (0.76 to 1.50)51.75 (0.75 to 4.08)
CB-ever2753085720.84 (0.56 to 1.25)590.93 (0.60 to 1.45)71.94 (0.72 to 5.21)
Asthma-current39531781161.48 (1.14 to 1.92)**1142.44 (1.85, 3.21)***144.54 (2.31 to 8.91)***
Asthma-ever80431962211.33 (1.11 to 1.57)**2382.75 (2.28 to 3.31)***286.49 (3.44 to 12.2)***
≥7 years§78331962211.41 (1.16 to 1.72)**2182.74 (2.21 to 3.41)***288.19 (4.22 to 15.9)***
Pneumonia-ever57431881741.43 (1.15 to 1.78)**1462.02 (1.58 to 2.57)***153.19 (1.66 to 6.14)**
≥7 years§46031881351.30 (1.02 to 1.65)*1111.79 (1.37 to 2.33)***92.18 (1.00 to 4.74)¶
<7 years1143188392.21 (1.38 to 3.56)**353.39 (2.05 to 5.60)***69.80 (3.70 to 25.9)***
  • *P<0.05, **p<0.01, ***p<0.001.

  • †Parent-reported bronchitis by age 7 categorised into none (reference=1, not shown), non-recurrent, recurrent (>5 episodes of coughing phlegm or ‘loose, or rattly’ cough lasting <1 month on average), and recurrent-protracted (>5 episodes, ≥1 month average duration).

  • ‡Multivariable models were adjusted for rurality of school, paternal occupation, family history of bronchitis, sibling number, maternal and paternal smoking, and participant sex.

  • §Doctor-diagnosed asthma | pneumonia recalled after childhood bronchitis was assessed that is, after age 7.

  • ¶P=0.050.

  • CB, chronic bronchitis.