Askie LM, et al. - In this prospectively planned meta-analysis of individual participant data from extremely preterm infants, researchers compared the effects of different target ranges for oxygen saturation as measured by pulse oximetry (Spo₂) on death or major morbidity. Outcomes revealed that lower Spo₂ target range and higher Spo₂ target range were not significantly different regarding the primary composite outcome of death or major disability at a corrected age of 18 to 24 months. They noted a higher risk of death and necrotizing enterocolitis, but a lower risk of retinopathy of prematurity treatment, in association with the lower Spo₂ target range.

Methods

• Individual participant data from 5 randomized clinical trials (conducted from 2005-2014) enrolling infants born before 28 weeks’ gestation was prospectively meta-analysed.
• Exposures included Spo₂ target range that was lower (85%-89%) vs higher (91%-95%).
• They assessed a composite of death or major disability (bilateral blindness, deafness, cerebral palsy diagnosed as ≥2 level on the Gross Motor Function Classification System, or Bayley-III cognitive or language score <85) at a corrected age of 18 to 24 months as the primary outcome.
• They assessed 16 secondary outcomes; these included the components of the primary outcome and other major morbidities.

Results

• Researchers noted randomization of a total of 4965 infants (2480 to the lower Spo₂ target range and 2485 to the higher Spo₂ range).
• The median gestational age of infants was 26 weeks (interquartile range, 25-27 weeks) and the mean birth weight was 832 g (SD, 190 g).
• In the lower Spo₂ target group, the primary outcome occurred in 1191 of 2228 infants (53.5%) and in the higher Spo₂ target group, it was noted in 1150 of 2229 infants (51.6%) (risk difference, 1.7% [95% CI, -1.3% to 4.6%]; relative risk [RR], 1.04 [95% CI, 0.98 to 1.09], P=.21).
• Of the 16 secondary outcomes assessed, 11 were of no significance; the lower Spo₂ target group was significantly favored by 2 of these 16 secondary outcomes, and the higher Spo₂ target group was significantly favored by 3 of them.
• Four hundred eighty four of 2433 infants (19.9%) in the lower Spo₂ target group and 418 of 2440 infants (17.1%) in the higher Spo₂ target group reported death (risk difference, 2.8% [95% CI, 0.6% to 5.0%]; RR, 1.17 [95% CI, 1.04 to 1.31], P=.01).
• In the lower Spo₂ and the higher Spo₂ target group, treatment for retinopathy of prematurity was administered to 220 of 2020 infants (10.9%) and 308 of 2065 infants (14.9%), respectively (risk difference, -4.0% [95% CI, -6.1% to -2.0%]; RR, 0.74 [95% CI, 0.63 to 0.86], P < .001).
• In this study, 227 of 2464 infants (9.2%) in the lower Spo₂ target group and 170 of 2465 infants (6.9%) in the higher Spo₂ target group suffered severe necrotizing enterocolitis (risk difference, 2.3% [95% CI, 0.8% to 3.8%]; RR, 1.33 [95% CI, 1.10 to 1.61], P=.003).