ABSTRACT
ObjectiveTo provide a thorough comparative study among state-of-the-art machine learning methods and statistical methods for determining in-hospital mortality in COVID-19 patients using data upon hospital admission; to study the reliability of the predictions of the most effective methods by correlating the probability of the outcome and the accuracy of the methods; to investigate how explainable are the predictions produced by the most effective methods. Materials and MethodsDe-identified data were obtained from COVID-19 positive patients in 36 participating hospitals, from March 1 to September 30, 2020. Demographic, comorbidity, clinical presentation and laboratory data were used as training data to develop COVID-19 mortality prediction models. Multiple machine learning and traditional statistics models were trained on this prediction task using a folded cross-validation procedure, from which we assessed performance and interpretability metrics. ResultsThe Stacking of machine learning models improved over the previous state-of-the-art results by more than 26% in predicting the class of interest (death), achieving 87.1% of AUROC and macro F1 of 73.9%. We also show that some machine learning models can be very interpretable and reliable, yielding more accurate predictions while providing a good explanation for the why. ConclusionThe best results were obtained using the meta-learning ensemble model - Stacking. State-of the art explainability techniques such as SHAP-values can be used to draw useful insights into the patterns learned by machine-learning algorithms. Machine-learning models can be more explainable than traditional statistics models while also yielding highly reliable predictions.
ABSTRACT
A new species is proposed based on material collected in the states of Minas Gerais, Sao Paulo, Santa Catarina, and Rio Grande do Sul, Brazil. The morphology, radula, and jaw are described and illustrated. The new species is compared to Belocaulus angustipes, the only species of the genus currently considered valid. The main differences are found in the penis. The new species has small projections, similar to tubercles, on the anterior region of the glans, which can be scattered or arranged in two, three or more longitudinal rows. The terminal extremity of the glans has digitiform margin. The penis base is short and poorly defined. The accessory gland is completely immersed in the tegument. The description of the new species extends the distribution range of Belocaulus for the states of Minas Gerais and Sao Paulo, Brazil...
