9– 18 Moreover, no visual or auscultatory finding consistently demonstrated high or low agreement in those studies. Studies in older infants and children with acute respiratory illnesses, including asthma, bronchiolitis, croup, and pneumonia, reported levels of interobserver agreement that varied from slight to almost perfect. This has not been measured for the respiratory examination in preterm infants. A necessary step in the validation of a physical examination finding as a diagnostic test or surrogate study endpoint is assessment of interobserver agreement. 7, 8 One of the many aims of PROP is to evaluate whether components of the respiratory physical examination assessed between 36 and 40 weeks’ postmenstrual age (PMA) in extremely preterm infants are predictive of respiratory outcomes at 1-year corrected age.
The Prematurity and Respiratory Outcomes Program (PROP) is a large, multicenter observational study of infants who are born at less than 29 weeks of gestation. 4– 6 Better methods are needed to quantify the severity of lung disease in the neonatal period and to predict which infants are likely to experience long-term respiratory complications. Bronchopulmonary dysplasia (BPD) is the most common chronic respiratory condition associated with preterm birth and is a strong predictor of multiple adverse health outcomes, including impairments in lung function and neurodevelopmental delay 1– 3 however, many former preterm infants who do not fulfill the diagnostic criteria for BPD also experience deficits in respiratory health through school age and into adulthood. Premature infants are at risk for significant, persistent respiratory morbidity.