Caucasian (N = 261) | African American (N = 113) | P value | |
---|---|---|---|
Infant characteristics | |||
Birth weight (grams) (N = 372), median (IQR*) | 3345 (3090, 3657) | 3147 (2892, 3430) | <0.001 |
Gestational age (weeks) (N = 371), median (IQR) | 39 (38,40) | 39 (38,40) | 0.498 |
Male gender, n (%) | 140 (54) | 67 (59) | 0.313 |
Age at enrollment (weeks), median (IQR) | 10 (6, 21) | 18 (7, 35) | <0.001 |
Breastfeeding, n (%) | 152 (58) | 46 (41) | 0.002 |
Daycare attendance, n (%) | 68 (26) | 39 (35) | 0.096 |
Secondhand smoke exposure (N = 371), n (%) | 158 (61) | 64 (57) | 0.486 |
Having siblings, n (%) | 198 (76) | 85 (75) | 0.894 |
Insurance type, n (%) | |||
Private | 111 (43) | 9 (8) | <0.001 |
Medicare | 135 (52) | 101 (89) | |
None | 15 (6) | 3 (3) | |
Season of enrollment, n (%) | |||
2004 – 2005 | 42 (16) | 21 (19) | 0.590 |
2005 – 2006 | 76 (29) | 38 (34) | |
2006 – 2007 | 75 (29) | 31 (27) | |
2007 – 2008 | 68 (26) | 23 (20) | |
RSV positive | 180 (69) | 59 (52) | 0.002 |
Lower respiratory tract infection vs. upper respiratory infection, n (%) | 213 (82) | 72 (64) | <0.001 |
Bronchiolitis severity score (n = 373), median (IQR) | 6.5 (3, 9) | 4 (1, 7) | <0.001 |
Maternal characteristics | |||
Maternal age at enrollment (years) | 27 (22, 31) | 24 (21, 27) | <0.001 |
Maternal education, years (n = 313), n (%) | |||
<12 | 42 (19) | 16 (17) | 0.004 |
12 | 56 (25) | 41 (44) | |
>12 | 122 (55) | 36 (39) | |
Maternal asthma, n (%) | 50 (19) | 27 (24) | 0.298 |