Hypothesis
Azithromycin given early to infants born before 30 weeks' gestation would increase survival without moderate or severe chronic lung disease of prematurity.
What failed
In 796 infants across 28 UK neonatal units, survival without moderate or severe chronic lung disease at 36 weeks was 42% with azithromycin vs 45% with placebo (adjusted OR 0.84, 95% CI 0.55–1.29, p = 0.43). Ureaplasma colonisation did not change the treatment effect.
Broken assumption
Macrolide prophylaxis prevents chronic lung disease in at-risk preterm infants, including those colonised with Ureaplasma.
Why
The trial, designed to settle conflicting systematic reviews, found no benefit overall or in Ureaplasma-colonised infants; adverse events were similar between arms.
From the published paper: Lowe et al. The Lancet Respiratory Medicine, 2024. ↗CC BY