Table 2.
Primary and secondary outcomes at low, moderate, high altitude
| Low altitude n=371,402 (68%) (22 hospitals) |
Moderate altitude n=83,202 (15%) (8 hospitals) |
High altitude n=95,562 (17%) (13 hospitals) |
p-valuea | |
|---|---|---|---|---|
| Overall PTB | 5.6 | 6.2 | 6.8 | 0.13 |
| Spontaneous PTB | 3.7 | 4.4 | 4.5 | 0.10 |
| PTB <34 weeks | 2.8 | 3.4 | 3.6 | 0.14 |
| Preeclampsia | 4.6 | 2.8 | 2.9 | 0.09 |
| SGA | 3.3 | 3.6 | 5.0 | 0.02 |
| Birthweight (g)b | 3218 (575) | 3159 (569) | 3041 (532) | <0.001 |
| Stillbirth | 1.3 | 1.5 | 1.7 | 0.11 |
| Apgar <6 at 5 min | 0.8 | 1.1 | 1.3 | 0.004 |
| Cesarean section | 28.0 | 26.6 | 20.6 | <0.001 |
Data are presented as percentages unless otherwise indicated
a
Tests of significance were adjusted for clustering by hospital using generalized estimating equations.
b
Mean (±SD)
PTB: preterm birth, SGA: small for gestational age