Ordinal bronchopulmonary dysplasia severity grade

Method

Bronchopulmonary dysplasia graded on the NIH consensus ordinal scale (none, mild, moderate, severe) at 36 weeks postmenstrual age, analysed as the odds of a higher grade.

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

Notes

SIGN TRAP, and it has already caught a published abstract. In PMID 36943265 the moderate-or-worse result is RR 1.16 (95 percent CI 1.04-1.29) while the abstract prose describes the exposure as inversely associated; a risk ratio above 1 for a severity outcome means MORE disease, not less. Read the point estimate, never the prose. Will also be confused with the binary severe-disease-at-36-weeks endpoint, a dichotomisation of this same scale, and with the composite that adds death before discharge.