Table 1.
Characteristics of the study population and frequency of neonatal sepsis.
| Characteristics | Full study population n = 793,128 | Neonatal sepsis n = 4,794 | |||
|---|---|---|---|---|---|
| n | % | n | % | Rate per 1,000 screened infants | |
| All infants | 793,128 | 100 | 4,794 | 100 | 6.0 |
| Infant sex | |||||
| Female | 387,221 | 48.8 | 2,084 | 43.5 | 5.4 |
| Male | 405,901 | 51.2 | 2,710 | 56.6 | 6.7 |
| Unknown | 6 | 0.0 | 0 | 0.0 | — |
| Gestational age (completed weeks) | |||||
| Mean ± SD | 38.86 ± 1.72a | 36.63 ± 3.92b | |||
| <34 | 11,820 | 1.5 | 1,024 | 21.4 | 86.6 |
| 34–36 | 44,754 | 5.6 | 805 | 16.8 | 18.0 |
| ≥37 | 731,841 | 92.3 | 2,946 | 61.5 | 4.0 |
| Missing | 4,713 | 0.6 | 19 | 0.4 | 4.0 |
| Birth weight (grams) | |||||
| Mean ± SD | 3,355.01 ± 550.98c | 2,882.14 ± 947.01d | |||
| <2,500 | 46,131 | 5.8 | 1,558 | 32.5 | 33.8 |
| ≥2,500 | 745,530 | 94.0 | 3,225 | 67.3 | 4.3 |
| Missing | 1,467 | 0.2 | 11 | 0.2 | 7.5 |
| Multiple birth | |||||
| No | 765,350 | 96.5 | 4,290 | 89.5 | 5.6 |
| Yes | 27,778 | 3.5 | 504 | 10.5 | 18.1 |
| Age at blood spot collection (hours) | |||||
| Median (IQR) | 28.45 (24.67–42.72) | 43.81 (25.73–72.77) | |||
| ≤72 | 739,436 | 93.2 | 3,565 | 74.36 | 4.8 |
| >72 | 53,682 | 6.8 | 1,229 | 25.6 | 22.9 |
| Missing | 10 | 0.0 | 0 | 0.0 | — |
| Any total parenteral nutritione | |||||
| No | 785,907 | 99.1 | 4,163 | 86.8 | 5.3 |
| Yes | 6,172 | 0.8 | 629 | 13.1 | 101.9 |
| Missing | 1,049 | 0.1 | f | — | — |
| Neonatal deathg | |||||
| No | 792,879 | 100.0 | 4,750 | 99.1 | 60. |
| Yes | 249 | 0.0 | 44 | 0.9 | 176.7 |
IQR: inter-quartile range; SD: standard deviation.
aMean (SD) within gestational age groups in full study population: <34 weeks: 31.2 (1.97); 34–36 weeks: 35.4 (0.76); ≥37 weeks: 39.2 (1.15).
bMean (SD) within gestational age groups in infants diagnosed with neonatal sepsis: <34 weeks: 30.3 (2.24); 34–36 weeks: 35.0 (0.84); ≥37 weeks: 39.3 (1.23).
cMean (SD) within birth weight groups in full study population: <2,500 grams: 2,099 (278); ≥2,500 grams: 3,433 (458).
dMean (SD) within birth weight groups in infants diagnosed with neonatal sepsis: <2,500 grams: 1,731 (475); ≥2,500 grams: 3,438 (522).
eTotal parenteral nutrition alone or in combination with other infant feeding method.
f<6 infants had missing information. The number has been combined with the ‘no’ category.
gRate of neonatal death: without a diagnosis of neonatal sepsis: 0.3 per 1,000; with a diagnosis of neonatal sepsis: 9.2 per 1,000.