Two-year death prediction models among patients with Chagas Disease using machine learning-based methods

Abstract

Chagas disease (CD) is recognized by the World Health Organization as one of the thirteen most neglected tropical diseases. More than 80% of people affected by CD will not have access to diagnosis and continued treatment, which partly supports the high morbidity and mortality rate. Machine Learning (ML) can identify patterns in data that can be used to increase our understanding of a specific problem or make predictions about the future. Thus, the aim of this study was to evaluate different models of ML to predict death in two years of patients with CD. ML models were developed using different techniques and configurations. The techniques used were: Random Forests, Adaptive Boosting, Decision Tree, Support Vector Machine, and Artificial Neural Networks. The adopted settings considered only interview variables, only complementary exam variables, and finally, both mixed. Data from a cohort study with CD patients called SaMi-Trop were analyzed. The predictor variables came from the baseline; and the outcome, which was death, came from the first follow-up. All models were evaluated in terms of Sensitivity, Specificity and G-mean. Among the 1694 individuals with CD considered, 134 (7.9%) died within two years of follow-up. Using only the predictor variables from the interview, the different techniques achieved a maximum G-mean of 0.64 in predicting death. Using only the variables from complementary exams, the G-mean was up to 0.77. In this configuration, the protagonism of NT-proBNP was evident, where it was possible to observe that an ML model using only this single variable reached G-mean of 0.76. The configuration that mixed interview variables and complementary exams achieved G-mean of 0.75. ML can be used as a useful tool with the potential to contribute to the management of patients with CD, by identifying patients with the highest probability of death. Trial Registration: This trial is registered with ClinicalTrials.gov, Trial ID: NCT02646943.

Conflict of interest statement

The authors have declared that no competing interests exist.

Figures

Fig 1. Flowchart of the process of selecting predictor variables based on cross-validation analysis for predicting death among patients with CD within two years of follow-up.

Fig 2. Flowchart of patients included and excluded from the cohort and of eligible patients in the study and in the models obtained.

SaMi-Trop Project. Minas Gerais.

Fig 3. Performance of models in predicting death for patients with CD, within two years, according to each machine learning technique adopted.

Fig 3A: Considering the interview variables. Fig 3B: Considering the variables of complementary exams. Fig 3C: Considering the variables of complementary exams, excluding the categorized NT-proBNP variable. Fig 3D: Considering the variables of complementary exams, considering only the NT-proBNP variable. Fig 3E: Considering the interview variables and complementary exam variables.

Fig 4. Importance of predictor variables of complementary exams for predicting death in patients with CD, within two years, according to Random Forests ranking.