Table 1 Subject characteristics

Demographics

Median birth year, (range)

2008 (1999–2014)

Males, no. (%)

88 (54%)

Race, no. (%)

 White

129 (79%)

 Black

14 (9%)

 Asian

2 (1%)

 Other

19 (11%)

Hispanic, no./total (%)

19/151 (13%)

Maternal history

Median maternal age (IQR)

33 (29.25—37)

Maternal asthma, no./total (%)

38/105 (36%)

Maternal hay fever, no./total (%)

31/105 (30%)

Maternal eczema, no./total (%)

26/106 (25%)

Maternal atopy, no./total (%)

60/106 (57%)

Neonatal history

Median gestational age, weeks (range)

26 1/7 (23 3/7—32)

Median birth weight, grams (range)

813 (455–1927)

Small for gestational age, no. (%)

13 (8%)

Multiple gestation, no. (%)

67/163 (41%)

Bronchopulmonary dysplasia, no. (%)

 None

16 (9%)

 Mild

15 (10%)

 Moderate

49 (30%)

 Severe

68 (41%)

 Unclassified

16 (10%)

Antenatal corticosteroid (any), no. (%)

114/136 (84%)

Antenatal steroid (complete), no. (%)

83/105 (78%)

Median ventilated days (IQR)

31 (8–49)

Median CPAP days (IQR)

25 (10–40)

Surfactant, no./total (%)

138/142 (97%)

PDA, no./total (%)

117/150 (78%)

PDA ligation, no./total (%)

50/148 (34%)

NEC, no./total (%)

25/148 (17%)

Intraventricular hemorrhage, no./total (%)

 Grade I/II

25/97 (27%)

 Grade III/IV/periventricular leukomalacia

7/97 (7%)

Gastrostomy tube, no./total (%)

42/142 (30%)

Tracheostomy, no./total (%)

14/145 (10%)

Postnatal steroids (NICU), no./total (%)

41/106 (33%)

Breastmilk nutrition at discharge no./total (%)

 Exclusive breastmilk

39/150 (26%)

 Mixed

54/150 (36%)

 Formula

57/150 (38%)

Resp support or O₂ at 36 wk, no./total (%)

117/149 (79%)

Resp support or O₂ at discharge, no./total (%)

80/160 (50%)

Tobacco exposure

Maternal tobacco use, no./total (%)

3/107 (3%)

Secondhand smoke exposure in home, no./total (%)

11/164 (7%)

Follow-up 0–3 years (n = 42 with data)

Received palivizumab

25/32 (60%)

Received flu shot

36/42 (86%)

ER or hospitalization for respiratory cause

19 (45%)

Hospitalization for respiratory cause

7 (17%)

Lower respiratory tract infection

14 (33%)

Spirometry

Mean age at spirometry, years (range)

6.7 (3–20)

Mean number of studies per subject, (range)

3.3 (1–18)