BPD | Non-BPD | Term | |||||
Stage 1 | Stage 2 | Stage 1 | Stage 2 | Stage 1 | Stage 2 | ||
Subjects n | 72 | 56 | 57 | 40 | 78 | 55 | |
Age at study years | 24.1±4.0 | 25.3±4.0 | 25.8±3.9** | ||||
Gestational age weeks | 27.1±2.1 | 27.1±2.1 | 31.0±2.5*** | 31.2±2.3*** | 39.7±1.4*** | 39.8±1.2*** | |
Birth weight g | 955±256 | 939±246 | 1238±222*** | 1234±223*** | 3514±456*** | 3556±429*** | |
Male | 39 (54) | 31 (55) | 22 (39) | 15 (38) | 40 (51) | 27 (49) | |
Antenatal steroids | 18 (25) | 16 (29) | 22 (39) | 13 (33) | |||
Maternal smoking | 16 (29) | 11 (25) | 14 (33) | 8 (29) | |||
Duration of hospital stay days | 104±43 | 106±45 | 50±26*** | 50±25*** | |||
Median Apgar score 1 min | 5.0 (3–6) | 5.0 (3–6)¶ | 6.0 (4–7.5) | 6.0 (4–8) | |||
Median Apgar score 5 min | 8.0 (7–8.8) | 8 (27–9)+ | 9.0 (8–9) | 9 (8–9) | |||
Post-natal steroids | 23 (32) | 19 (34) | |||||
Median duration oxygen >60% h | 10.5 (2.8–53.8) | 10.0 (2–63.5)§ | |||||
Median duration IPPV h | 841.0 (449.8–1347) | 783 (425.8–1478.8)¶ | |||||
Surfactant | 22 (31)ƒ | 18 (32) | |||||
Current smoker# | 16 (22) | 11 (18)ƒ | 17 (30) | 8 (18)¶ | 23 (30) | 15 (24)ƒ |
Data are presented as mean±sd, n (%) or median (interquartile range), unless otherwise stated. IPPV: intermittent positive pressure ventilation. #: those who were daily smokers at the time of testing; ¶: n=2 missing data; +: n=4 missing data; §: n=7 missing data; ƒ: n=1 missing data. **: p<0.01; ***: p<0.001.