Targeting oxygen saturation below 90% was associated with increased mortality at 2 years in a post hoc analysis of BOOST-II data.
The randomized Australian and U.K. Benefits of Oxygen Saturation Targeting (BOOST-II) trials compared oxygen saturation targets of 85%–89% and 91%–95% in 2100 preterm infants. Midway through enrollment, a calibration error in the oximeters was adjusted, and the corrected oximeters were used thereafter. An interim analysis at age 36 weeks among infants measured with corrected oximeters showed significantly higher mortality in the lower-target group, prompting investigators to stop enrollment early (NEJM JW Pediatr Adolesc Med Jul 2013 and N Engl J Med 2013 May 5; [e-pub]). Now, the investigators report outcomes at corrected gestational age of 2 years.
Analysis of the primary outcome (death or disability) in each trial individually showed no s…