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.

早产和感染是新生儿死亡的常见原因。在这项研究中，我们旨在开发一个诺模图，以根据早产儿的危险因素评估晚期败血症的个体先验概率。这项研究是在三个中心进行的回顾性和前瞻性队列研究。2014年1月至2017年12月的数据用于开发队列，2018年1月至2018年12月的数据用于验证队列。在发育队列中，我们确定了早产儿迟发败血症的预测变量，并从中获得了诺模图。然后，我们建立了有无甲状腺功能的诺模图，以预测迟发性败血症。诺模图在有关区分和校准的验证队列中得到验证。发育和验证队列分别包括1256名和452名早产儿。我们发现早产儿甲状腺功能低下可能增加晚期感染的发生率。结合甲状腺功能，出生体重，气管插管使用和脐静脉导管持续时间的预测模型已得到验证，并将其开发为诺模图，用于预测早产儿早发性败血症。本研究中的诺法图可能有助于临床评估和治疗决策。脐静脉导管的长度和持续时间已得到验证并发展为诺模图，用于预测早产儿的迟发性败血症。本研究中的诺法图可能有助于临床评估和治疗决策。脐静脉导管的长度和持续时间已得到验证并发展为诺模图，用于预测早产儿的迟发性败血症。本研究中的诺法图可能有助于临床评估和治疗决策。