Comparing different venous thromboembolism risk assessment machine learning models in Chinese patients.

OBJECTIVE: Venous thromboembolism (VTE) is a fatal complication and the most common preventable cause of death in hospitals. The risk-to-benefit ratio of thromboprophylaxis depends on the performance of the risk assessment model. A linear model, the Padua model, is recommended for medical inpatients in the United States but is not suitable for Chinese inpatients due to differences in race and disease spectrum. Currently, machine learning (ML) methods show advantages in modeling complex data patterns and have been applied to clinical data analysis. This study aimed to build VTE risk assessment ML models among Chinese inpatients and compare the predictive validity of the ML models with that of the Padua model. METHODS: We used 376 patients, including 188 patients with VTE, to build a model and then evaluate the predictive validity of the model in a consecutive clinical dataset from Peking Union Medical College Hospital. Nine widely used ML methods were trained on the model derivation set and then compared with the Padua model. RESULTS: Among the nine ML methods, random forest (RF), boosting-based methods, and logistic regression achieved a higher specificity, Youden index, positive predictive value, and area under the receiver operating characteristic curve than the Padua model on both the test and clinical validation sets. However, their sensitivities were inferior to that of the Padua model. Combined with the receiver operating characteristic curve, RF, as the best performing model, maintained high specificity with relatively better sensitivity and captured VTE patients' patterns more precisely. CONCLUSIONS: Advances in ML technology provide powerful tools for medical data analysis, and choosing models conforming to the disease pattern would achieve good performance. Popular ML models do not surpass the Padua model on all indicators of validity, and the drawback of low sensitivity should be improved upon in the future.

[Assessment of pulmonary function in SARS patients during the convalescent period].

OBJECTIVE: To investigate the pulmonary function in severe acute respiratory syndrome (SARS) patients during the convalescent period. METHODS: Followup 89 outpatients of SARS. The follow-up study included interview, physical examination, and pulmonary function test. RESULTS: The interval between hospital discharge and functional assessment was 1.75 +/- 0.53 months (0.5-3.4 months). Mild to moderate abnormalities in pulmonary function were found in 48 patients (53.9%). Diffusion capacity for carbon monoxide (DLco) was impaired in 38 patients (42.7%); in 7 patients (7.9%), lung function was restrictive defect combined DLco impairment; Other patterns of impairment were revealed in 3 patient. Dyspnea during acute phase and CT during the convalescent period were found to have significant influences on DLco and total lung capacity (TLC). CONCLUSIONS: Diffusing capacity impairment as well as restrictive defect persist in convalescence SARS.