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

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. Then we built nomograms, for with and without thyroid function, to predict late-onset sepsis. The nomogram was validated in the validation cohort concerning discrimination and calibration. A total of 1256 and 452 preterm infants were included in the development and validation cohort, respectively. We found thyroid hypofunction in preterm infants could increase the incidence of late-onset infection. The prediction model incorporated thyroid function, birth weight, use of endotracheal intubation, and duration of umbilical venous catheters was validated and developed as a nomogram for predicting late-onset sepsis in preterm infants. Nomogram in this study may contribute to clinical assessment and treatment decisions.