Table 1.
Characteristics of infants with samples included in analysis, by week
|
Hospital 1, week 1 |
Hospital 2, week 1 |
Hospital 1, week 2 |
Hospital 2, week 2 |
|||||
|---|---|---|---|---|---|---|---|---|
|
2010 |
2011 |
2010 |
2011 |
2010 |
2011 |
2010 |
2011 |
|
| n = 9 | n = 13 | n = 12 | n = 17 | n = 11 | n = 13 | n = 15 | n = 21 | |
| Birthweight, mean ± sd (g) |
963 ± 216 |
965 ± 261 |
938 ± 234 |
953 ± 223 |
985 ± 193 |
995 ± 261 |
914 ± 216 |
962 ± 207 |
| Birth length, mean ± sd (cm) |
35.8 ± 3.0 |
35.2 ± 2.9 |
34.0 ± 3.1 |
34.9 ± 2.9 |
35.8 ± 2.7 |
35.5 ± 2.9 |
33.7 ± 3.5 |
36.3 ± 6.9 |
| GA at birth, weeks (25th–75th percentile) |
26 (26–28) |
28 (26–28) |
27 (26.8–28) |
27 (26–28) |
26 (25.5–27.5) |
28 (26–28) |
27 (26–28) |
27 (26–28) |
| Male (%) |
5 (56%) |
6 (46%) |
5 (42%) |
7 (41%) |
4 (36%) |
7 (54%) |
6 (40%) |
11 (52%) |
| Hispanic (%) |
0 (0%) |
1 (7.7%) |
1 (8.3%) |
0 (0%) |
0 (0%) |
1 (7.7%) |
1 (6.7%) |
0 (0%) |
| Black (%) |
5 (56%) |
6 (46%) |
8 (67%) |
6 (35%) |
3 (27%) |
2 (15%) |
10 (67%) |
8 (38%) |
| Cesarean section (%) |
5 (56%) |
5 (38%) |
6 (50%) |
10 (59%) |
6 (55%) |
6 (46%) |
7 (47%) |
10 (48%) |
| Maternal abx at delivery (%) |
6 (67%) |
10 (77%) |
11 (92%) |
17 (100%) |
8 (73%) |
10 (77%) |
14 (93%) |
20 (95%) |
| Maternal age ± sd (years)a |
27.4 ± 1.6 |
28.0 ± 1.4 |
22.5 ± 4.9 |
x27.8 ± 6.1 |
28.5 ± 6.7 |
29.1 ± 5.6 |
21.9 ± 5.1 |
27.7 ± 5.7 |
| Maternal parity (25th–75th percentile) |
2 (1–3) |
1 (1–3) |
2 (1–3) |
2 (1–2) |
2 (1.5–3) |
1 (1–3) |
2 (1–3) |
1 (1–3) |
| Preeclampsia (%) |
1 (11%) |
2 (15%) |
3 (25%) |
1 (5.8%) |
1 (9.1%) |
3 (2.3%) |
3 (20%) |
1 (4.8%) |
| Day of life of sample collection, median (25th–75th percentile)b |
7 (5–7) |
6 (5–8) |
6 (5.8–6.3) |
8 (7–8) |
13 (13–14) |
14 (11–14) |
11 (10–12) |
10 (10–12) |
| Days on abx in the first 7 days ± sd |
4.0 ± 2.6 |
3.1 ± 2.1 |
4.7 ± 2.0 |
3.8 ± 1.7 |
NA |
NA |
NA |
NA |
| Days on abx in the first 14 days ± sd |
NA |
NA |
NA |
NA |
4.4 ± 3.1 |
3.6 ± 3.8 |
7.6 ± 4.4 |
5.4 ± 3.4 |
| Days of life of first enteral feed, mean ± sd |
4.6 ± 3.7 |
2.5 ± 0.66 |
3 ± 1.3 |
2.8 ± 1.2 |
3.6 ± 1.5 |
2.7 ± 0.75 |
3.6 ± 2.4 |
3 ± 1.6 |
| Median percent formula feeds in the first 7 days (25th–75th percentile) |
0% (0%, 0%) |
0% (0%, 0%) |
0% (0%, 35.7%) |
0% (0%, 25%) |
NA |
NA |
NA |
NA |
| Median percent formula feeds in the first 14 days (25th–75th percentile) | NA | NA | NA | NA | 0% (0%, 0%) | 0% (0%, 0%) | 8.3% (0%, 31.7%) | 6.7% (0%, 18.2%) |
aSignificantly different between years in hospital 2 week 1, p = 0.015, and hospital 2 week 2, p = 0.003; bsignificantly different between years in hospital 2 week 1, p < 0.01. Data in bold are values which are significantly different.