Outcomes
| Low threshold group (n=328) | High threshold group (n=325) | P value | |
| Primary outcome | |||
| Death up to 2 years or unfavourable outcome | 120/305 (39) | 147/296 (50) | |
| OR (<50 vs <25) (95% CI) | 1.54 (1.09 to 2.17)* | 0.0167 | |
| Secondary outcomes | |||
| Deaths up to 2 years, n/total n(%)† | 74/306 (24) | 91/300 (30) | |
| OR (<50 vs <25) (95% CI) | 1.36 (0.93 to 1.99) | 0.1067 | |
| Unfavourable outcome (excluding deaths), n/total n (%) | 46/231 (20) | 56/205 (27) | |
| OR (<50 vs <25) (95% CI) | 1.53 (0.95 to 2.46) | 0.0788 | |
| Participants who have cerebral palsy that impaired independent walking, n/total n (%)‡ | 23/229 (10) | 26/203 (13) | |
| Participants who have global development delay, n/total n (%)‡ | 33/228 (14) | 44/204 (22) | |
| Participants who have a severe seizure disorder requiring treatment, n/total n (%)‡ | 4/225 (2) | 7/200 (4) | |
| Participants who have hearing impairment not corrected by hearing aids, n/total n (%)‡ | 3/227 (1) | 5/203 (2) | |
| Participants who have bilateral cortical visual impairment with no useful vision, n/total n (%)‡ | 2/225 (1) | 3/200 (2) | |
| Participants who died or required respiratory support at 2 years of corrected age | 83/301 (28) | 113/296 (38) | |
| OR (<50 vs <25) (95% CI) | 1.62 (1.12 to 2.34) | ||
| Participants who were dependent on oxygen or respiratory support at 2 years of corrected age | 9/228 (4) | 22/207(11) | |
| OR (<50 vs <25) (95% CI) | 2.86 (1.25 to 6.51) | ||
All ORs have been adjusted for GA and presence of IUGR as covariates and centre has been adjusted for using a random effect. Marginal effects are reported.
*The OR has been adjusted for GA and presence of IUGR as covariates and centre has been adjusted for using a random effect. Outcome data were missing for 52 participants (23 in the <25 arm and 29 in the <50 arm). The OR is presented as <50 arm vs <25 arm. Marginal effects are reported.
†Includes five participants who were known to be alive at 2 years, but it was not possible to establish their neurodevelopmental outcome due to insufficient information.
‡Note differing denominators for component parts of neurodevelopmental outcome due to missing data, but unfavourable outcome could still be assigned based on the presence of another adverse factor.
GA, gestational age; IUGR, intrauterine growth restriction.