Mortality by birth weight; extremely low birth weight (ELBW, <1000 g), very low birth weight (VLBW, 1000–<1500 g), low birth weight (LBW, 1500–<2500 g), normal (2500–<4000 g) and large for gestational age (LGA, ≥4000 g)
| Mortality | Time to death Time to death in days* | ||||
|---|---|---|---|---|---|
| Birth weight | Pooled estimates | Hospital-specific estimates | |||
| n (%) | 95% CI | Median (%) | Range (%) | Median (range) | |
| ELBW (n=16) | 14 (88) | 58 to 97 | 100 | 0–100 | 1 (<1–54) |
| VLBW (n=100) | 51 (51) | 32 to 70 | 33 | 0–100 | 1 (<1–15) |
| LBW (n=340) | 49 (14) | 9 to 22 | 13 | 0–47 | 1 (<1–93) |
| Normal (n=559) | 62 (11) | 6.5 to 18 | 7.7 | 0–50 | 1 (<1–14) |
| LGA (n=50) | 4 (8) | 3.6 to 17 | 0 | 0–33 | 1.5 (<1–20) |
| Total (n=1065)† | 180 (17) | 11 to 24 | 16.4 | 0–46‡ | 1 (<1–93) |
*Time to death from admission.
†In 15% of cases (184/1249), it was not possible to determine the outcome by birth weight (either due to missing outcome or birth weight data).
‡Four hospitals recorded no mortality, possibly representing a ‘retrieval’ bias in obtaining mortality files.