Dynamic Nomogram for Subsyndromal Delirium in Adult Intensive Care Unit: A Prospective Cohort Study

Junning Cheng,* Yuewen Lao,* Xiangping Chen, Xiaoting Qiao, Weijing Sui, Xiaoyan Gong, Yiyu Zhuang Nursing Department, Zhejiang University School of Medicine Sir Run Run Shaw Hospital, Hangzhou, People’s Republic of China*These authors contributed equally to this workCorrespondence: Yiyu Zhuang, Nursing Department, Zhejiang University School of Medicine Sir Run Run Shaw Hospital, Hangzhou, People’s Republic of China, Tel +8613588708076, Email zhuangyy@zju.edu.cnPurpose: To develop a dynamic nomogram of subsyndromal delirium (SSD) in intensive care unit (ICU) patients and internally validate its efficacy in predicting SSD.Patients and Methods: Patients who met the inclusion and exclusion criteria in the ICU of a tertiary hospital in Zhejiang from September 2021 to June 2022 were selected as the research objects. The patient data were randomly divided into the training set and validation set according to the ratio of 7:3. The least absolute shrinkage and selection operator (LASSO) and multivariate logistic regression were used to screen the predictors of SSD, and R software was used to construct a dynamic nomogram. Receiver operating characteristic (ROC) curve, calibration band and decision curve were used to evaluate the discrimination, calibration and clinical effectiveness of the model.Results: A total of 1000 eligible patients were included, including 700 in the training set and 300 in the validation set. Age, drinking history, C reactive protein level, APACHE II, indwelling urinary catheter, mechanical ventilation, cerebrovascular disease, respiratory failure, constraint, dexmedetomidine, and propofol were predictors of SSD in ICU patients. The ROC curve values of the training set was 0.902 (95% confidence interval: 0.879– 0.925), the best cutoff value was 0.264, the specificity was 78.4%, and the sensitivity was 88.0%. The ROC curve values of the validation set was 0.888 (95% confidence interval: 0.850– 0.930), the best cutoff value was 0.543, the specificity was 94.9%, and the sensitivity was 70.9%. The calibration band showed good calibration in the training and validation set. Decision curve analysis showed that the net benefit in the model was significantly high.Conclusion: The dynamic nomogram has good predictive performance, so it is a precise and effective tool for medical staff to predict and manage SSD in the early stage.Keywords: subsyndromal delirium, intensive care unit, nomogram, prediction model, LASSO