Abstract 14313: Machine Learning for Prediction of Low Density Lipoprotein Cholesterol in Fasting and Non-fasting Patients With and Without HIV Infection

Circulation ◽  
2020 ◽  
Vol 142 (Suppl_3) ◽  
Author(s):  
Mariam N Rana ◽  
Chang Kim ◽  
Chris T Longenecker ◽  
Sadeer Al-Kindi

Background: Low-density lipoprotein cholesterol (LDL-C) is commonly estimated from total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C) and triglycerides (TG) using predefined equations which assume fixed or varying relationships between these parameters and may under- or overestimate LDL-C. Machine learning (ML) algorithms allow prediction of complex non-linear relationships. We, therefore, sought to investigate the utility of ML to predict LDL-C in comparison with two widely-used methods (Friedewald and Hopkins). Methods: We identified 7397 direct LDL-C (4716 HIV, 2060 uninfected controls) measurements in the Women's Interagency HIV Study (WIHS), a prospective study of women with and without HIV undergoing serial assessments. We trained and optimized 5 ML methods (linear regression, random forest, gradient boosting machine, support vector machine, and neural networks) to predict LDL-C using TC, HDL-C, and TG in 80% of the measurements and tested model performance in a holdout test set (20% of the measurements). Results: Overall, the support vector machine model had the best performance characteristics, outperforming Friedewald’s and Hopkins methods with higher R 2 , lower root mean square error and lower mean absolute error. The support vector machine model performance remained superior in participant subgroups with and without HIV and those with non-fasting measurements. Model performance parameters for the test dataset are shown in the Figure. Conclusions: A support vector machine learning model predicts directly measured LDL-C more accurately than Friedewald and Hopkins methods, especially in non-fasting patients with HIV. Further studies are needed to provide external validation.

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Hua Liu ◽  
Hua Yuan ◽  
Yongmei Wang ◽  
Weiwei Huang ◽  
Hui Xue ◽  
...  

AbstractAccumulating studies appear to suggest that the risk factors for venous thromboembolism (VTE) among young-middle-aged inpatients are different from those among elderly people. Therefore, the current prediction models for VTE are not applicable to young-middle-aged inpatients. The aim of this study was to develop and externally validate a new prediction model for young-middle-aged people using machine learning methods. The clinical data sets linked with 167 inpatients with deep venous thrombosis (DVT) and/or pulmonary embolism (PE) and 406 patients without DVT or PE were compared and analysed with machine learning techniques. Five algorithms, including logistic regression, decision tree, feed-forward neural network, support vector machine, and random forest, were used for training and preparing the models. The support vector machine model had the best performance, with AUC values of 0.806–0.944 for 95% CI, 59% sensitivity and 99% specificity, and an accuracy of 87%. Although different top predictors of adverse outcomes appeared in the different models, life-threatening illness, fibrinogen, RBCs, and PT appeared to be more consistently featured by the different models as top predictors of adverse outcomes. Clinical data sets of young and middle-aged inpatients can be used to accurately predict the risk of VTE with a support vector machine model.


Processes ◽  
2021 ◽  
Vol 9 (6) ◽  
pp. 910
Author(s):  
Seok-Hwan Oh ◽  
Hyoung Jin Lee ◽  
Tae-Seong Roh

The correlation between solid propellant grain configuration and burning surface area profile is a complicated nonlinear problem. Nonlinear optimization has been adopted to design grain configurations that satisfied the objective area profiles. However, as conventional design methods are impractical, with limited performance, it is necessary to investigate alternatives. Useful information for grain design can be obtained by analyzing the aforementioned correlation. However, this aspect has not been studied owing to the requirement of large amounts of data and analysis techniques. In this study, machine learning was used to develop a new design method. The objective of machine learning was to train a model to classify classes of data. The database stores various sets of configuration variables and their classes. The proposed Gaussian kernel-based support vector machine model predicts the class of newly designed grains. The results verified that the model accurately predicted the class of the set of configuration variables and can be used to modify the set of configuration variables to satisfy the requirement. Thus, it was confirmed that machine learning is an appropriate approach to grain design; however, further research is needed to analyze its practicality.


2019 ◽  
Vol 15 (2) ◽  
pp. 177-182
Author(s):  
Bayu Sugara ◽  
Agus Subekti

Seiring dengan perkembangan ilmu pengetahuan dan teknologi informasi, kehadiran machine learning dibidang komputer telah menjadi salah satu tren dan menarik banyak perhatian. Penggunaan machine learning tidak terlepas dari  penggunaan data dalam pembelajarannya. Data yang besar merupakan data yang sering digunakan dalam proses pembelajaran machine learning. Perkembangan machine learning yang sangat pesat dapat memungkinkan data yang besar cepat pula terakumulasi. Namun, jarang ditemukan machine learning menggunakan data yang kecil (small dataset) dalam proses pembelajarannya. Small dataset ini biasanya bersifat private yang diambil dari sebuah organisasi yang akan dijadikan objek penelitian seperti data bank, rumah sakit, pabrik dan perusahaan jasa. Dalam penelitian ini peneliti menggunakan  algoritma Support Vector Machine dan k-fold corss validation untuk menguji nilai keakuratan small dataset serta menggunakan teknik ensemble untuk mengetahui seberapa pengaruhnya teknik ensemble terhadap algoritma Support Vector Machine. Hasil dari penelitian ini menunjukkan bahwan teknik ensemble dapat meningkatkan performa akurasi pada Support Vector Machine. Model algoritma SVM dan teknik ensemble dengan poly kernel menunjukkan nilai akurasi terbaik yaitu sebesar 91%.


2021 ◽  
Vol Publish Ahead of Print ◽  
Author(s):  
Tony Dong ◽  
Mariam N. Rana ◽  
Chris T. Longenecker ◽  
Sanjay Rajagopalan ◽  
Chang H. Kim ◽  
...  

Author(s):  
Tsigalou Christina ◽  
Panopoulou Maria ◽  
Papadopoulos Charalambos ◽  
Karvelas Alexandros ◽  
Tsairidis Dimitrios ◽  
...  

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