The inverse groups?
Wirtschafter
David D
DD
D001997:Bronchopulmonary Dysplasia / Q000453:epidemiology / Q000517:prevention & control*; D003428:Cross Infection / Q000453:epidemiology / Q000517:prevention & control*; D019317:Evidence-Based Medicine; D006801:Humans; D007231:Infant, Newborn; D007363:Intensive Care Units, Neonatal / Q000458:organization & administration*; D011785:Quality Assurance, Health Care; D016032:Randomized Controlled Trials as Topic / Q000379:methods*