Probability Threshold Optimization for Classification of COVID-19 Patients with Higher Mortality Risk: A Case Study from the North-Eastern Region in North Macedonia
Dragana Mogilevska-Gruevska, Ilija Gruevski, Golubinka Boshevska, Stevan Gaber · European Journal of Medical and Health Research · 2024
Research goal: The goal of this research is to identify, compare and demonstrate some available methodological approaches which are sufficient to draw the optimal probability threshold, particularly in the case of classification of infected patients with increased risk of dying from COVID-19. The presented methodologies generate identical results if the purpose of classification is to maximize the prognosis accuracy from the point of sensitivity. Sample: As part of the whole population, the sample counts 1013 patients from the north-eastern region of the Republic of North Macedonia. Methodology: The general methodological frame used to calculate and forecast the probabilities of death outcome from COVID-19 is the binary logistic regression. In extension, we applied the rules of maximum sum and maximum product as well as the so-called Youden Index for the purpose of optimization of the probability threshold. The principals of the ROC curve in addition with the Index of Union was also helpful for the same purpose. Prognosis accuracy was evaluated through the status of patient according to the rules of “golden standard” in which sensitivity, specificity and the general accuracy of prognosis play a crucial role. Results: Accordingly, the results from the research indicate that the optimal probability threshold or “cut-off” point that provides maximal accuracy, particularly from the perspective of sensitivity in the prognosis is 0,1. In that point, the coefficient of sensitivity (the percentage of true positively predicted death cases in respect to all death cases from the sample) is measured 85,71%. Conclusion: The applied methodological approaches offer scientifically sound foundations in the context of mortality risk evaluation and classification of COVID-19 patients. Then targeted patients will be subject of precaution with strict measures, protocols and more aggressive treatment in order to minimize the chances of death outcome.