Preterm birth and infection are common causes of neonatal death. In this study, we aimed to develop a nomogram for assessing the individual prior probability of late-onset sepsis on the basis of risk factors in preterm infants. This study is a mixed retrospective and prospective cohort study conducted in three centers. Data from January 2014 to December 2017 was used for the development cohort, and data from January 2018 to December 2018 was used for the validation cohort. In the development cohort, we identified the predicting variables of late-onset sepsis in preterm infants, from which a nomogram was obtained. | Development and validation of a nomogram for predicting late-onset sepsis in preterm infants on the basis of thyroid function and other risk factors Mixed retrospective and prospective cohort study