Foinquinos Juliana, Duarte Maria do Carmo, Figueiroa Jose Natal, Correia Jailson B, Cavalcanti Nara Vasconcelos
Instituto de Medicina Integral Prof. Fernando Figueira, Recife, Brazil.
Universidade de Pernambuco, Recife, Brazil.
J Trop Med. 2021 Dec 22;2021:6688444. doi: 10.1155/2021/6688444. eCollection 2021.
To perform a temporal validation of a predictive model for death in children with visceral leishmaniasis (VL).
A temporal validation of a children-exclusive predictive model of death due to VL (Sampaio et al. 2010 model), using a retrospective cohort, hereby called validation cohort. The validation cohort convenience sample was made of 156 patients less than 15 years old hospitalized between 2008 and 2018 with VL. Patients included in the Sampaio et al. 2010 study are here denominated derivation cohort, which was composed of 546 patients hospitalized in the same hospital setting in the period from 1996 to 2006. The calibration and discriminative capacity of the model to predict death by VL in the validation cohort were then assessed through the procedure of logistic recalibration that readjusted its coefficients. The calibration of the updated model was tested using Hosmer-Lemeshow test and Spiegelhalter test. A ROC curve was built and the value of the area under this curve represented the model's discrimination.
The validation cohort found a lethality of 6.4%. The Sampaio et al. 2010 model demonstrated inadequate calibration in the validation cohort (Spiegelhalter test: =0.007). It also presented unsatisfactory discriminative capacity, evaluated by the area under the ROC curve = 0.618. After the coefficient readjustment, the model showed adequate calibration (Spiegelhalter test, =0.988) and better discrimination, becoming satisfactory (AUROC = 0.762). The score developed by Sampaio et al. 2010 attributed 1 point to the variables dyspnea, associated infections, and neutrophil count <500/mm; 2 points to jaundice and mucosal bleeding; and 3 points to platelet count <50,000/mm. In the recalibrated model, each one of the variables had a scoring of 1 point for each.
The temporally validated model, after coefficient readjustment, presented adequate calibration and discrimination to predict death in children hospitalized with VL.
对内脏利什曼病（VL）患儿死亡预测模型进行时间验证。
采用回顾性队列对VL所致儿童死亡的专属预测模型（桑帕约等人2010年模型）进行时间验证，此队列称为验证队列。验证队列的便利样本由2008年至2018年间因VL住院的156名15岁以下患者组成。桑帕约等人2010年研究中纳入的患者在此称为推导队列，该队列由1996年至2006年期间在同一医院环境中住院的546名患者组成。然后通过逻辑重新校准程序评估模型在验证队列中预测VL死亡的校准和判别能力，该程序重新调整了其系数。使用Hosmer-Lemeshow检验和Spiegelhalter检验测试更新后模型的校准。构建ROC曲线，该曲线下面积值代表模型的判别能力。
验证队列的致死率为6.4%。桑帕约等人2010年模型在验证队列中显示校准不足（Spiegelhalter检验：=0.007）。通过ROC曲线下面积评估，其判别能力也不令人满意（=0.618）。系数重新调整后，模型显示校准充分（Spiegelhalter检验，=0.988）且判别能力更好，变得令人满意（AUROC=0.762）。桑帕约等人2010年制定的评分对呼吸困难、合并感染和中性粒细胞计数<500/mm³的变量赋予1分；对黄疸和黏膜出血赋予2分；对血小板计数<50,000/mm³赋予3分。在重新校准的模型中，每个变量的评分为1分。
经过系数重新调整的时间验证模型，在预测因VL住院儿童的死亡方面表现出充分的校准和判别能力。
