Composite of death or severe bronchopulmonary dysplasia

Method

First occurrence of either death before 36 weeks postmenstrual age or severe bronchopulmonary dysplasia at 36 weeks postmenstrual age, pooled as a relative risk.

The method is part of the endpoint identity. Studies measuring the same quantity by a different method are held as separate endpoints.

Notes

Will be confused with either of its two components. The composite exists specifically because mortality is a COMPETING RISK: an infant who dies cannot be diagnosed at 36 weeks, so an intervention that increases deaths can make the disease-alone rate look better. A component result must never be substituted for this composite, nor this composite for a component -- that substitution is exactly the error the composite was designed to prevent. THIS PARAGRAPH USED TO SAY the two components were "both recorded as their own nodes in this round". They were not. CAT:outcome/death-before-discharge-preterm existed; the severe-disease component did not exist at all, and was minted on 2026-08-27 as CAT:outcome/severe-bpd-at-36-weeks below. The sentence had asserted a sibling into being and nothing checked it, which is why PMID 40180500's PRIMARY OUTCOME -- severe BPD, adjusted RR 1.06 -- had nowhere to go and was put down in `omitted`. Note also that the surviving component node is death before DISCHARGE while this composite's own arm is death before 36 WEEKS PMA; those are different windows and the two still do not decompose cleanly.