(A) Background and clinical characteristics of young adults hospitalised for bronchiolitis in infancy compared with control subjects. | |||||||

Postbronchiolitis | Control | P value* | |||||

N | N | ||||||

Males, n (%) | 225 | 117 (52.0) | 167 | 82 (49.1) | 0.57 | ||

Gestational age at birth <36 weeks, n (%) | 204 | 4 (2.0) | 164 | 1 (0.6) | 0.266 | ||

Birth weight, grams, mean (SD) | 197 | 3526 (619) | 164 | 3661 (515) | 0.024 | ||

At follow-up | |||||||

Age, years, median (quartiles) | 225 | 19.4 (18.6, 20.3) | 167 | 19.2 (18.6, 20.6) | 0.241 | ||

BMI, kg/m^{2}, median (quartiles) | 223 | 23.5 (21.0, 27.4) | 166 | 22.7 (21.2, 25.5) | 0.076 | ||

Height, cm, median (quartiles) | 224 | 172.5 (167.0, 181.8) | 166 | 175.0 (167.6, 182.0) | 0.218 | ||

Weight, kg, median (quartiles) | 224 | 70.0 (63.1, 83.4) | 166 | 71.0 (63.0, 80.1) | 0.651 | ||

Use of inhaled corticosteroids the last 12 months, n (%) | 223 | 25 (11.2) | 166 | 9 (5.4) | 0.046 | ||

Personal smoking, n (%) | 225 | 20 (8.9) | 167 | 8 (4.8) | 0.119 | ||

Household smoking ever, n (%) | 225 | 74 (32.9) | 167 | 41 (24.6) | 0.073 | ||

Atopic dermatitis, n (%) | 215 | 50 (23.3) | 164 | 35 (21.3) | 0.658 | ||

Family history of atopy, n (%) | 225 | 155 (68.9) | 167 | 107 (64.1) | 0.316 | ||

(B) Clinical variables at hospitalisation for bronchiolitis for all postbronchiolitis subjects and for the RSV group compared with the non-RSV group. | |||||||

All postbronchiolitis | RSV | Non-RSV | P value† | ||||

N | N | N | |||||

Age at hospitalisation, months, median (quartiles) | 225 | 4.2 (2.3, 6.8) | 128 | 3.8 (2.0, 5.8) | 64 | 4.5 (2.4, 7.8) | 0.041 |

Weight at hospitalisation, grams, mean (SD) | 197 | 6911 (1905) | 112 | 6539 (1823) | 54 | 7107 (1818) | 0.062 |

Previous history of BPO, n (%) | 225 | 32 (14.2) | 128 | 13 (10.2) | 64 | 12 (18.8) | 0.095 |

Length of hospital stay, days, median (quartiles) | 225 | 3.0 (1.0, 4.0) | 128 | 3.0 (2.0, 5.5) | 64 | 2.0 (1.0, 3.0) | 0.001 |

Corticosteroids (inhaled/systemically) given during admission, n (%) | 225 | 15 (6.7) | 128 | 6 (4.7) | 64 | 6 (9.4) | 0.206 |

P values are from Student’s t-test for normally distributed variables given as means (SDs), Mann-Whitney U test for continuous variables not normally distributed given as medians (quartiles) and Pearson χ

^{2}test for dichotomous variables. Bold values denote statistical significance at the p<0.05 level.*P values comparing the postbronchiolitis group and the control group.

†P values comparing the RSV group and the non-RSV group.

BMI, body mass index; BPO, broncopulmonal obstruction; n, number of participants with the characteristic described; N, number of participants with available data; RSV, respiratory syncytial virus.