CRP and chronic kidney disease: Several features were significantly different between the two groups namely, age, diet, obesity, diabetes, CKD, ESRD, cough, c reactive protein, calcium level, chloride level, CO2 level, creatinine, ferritin level etc. We applied a correlation matrix to identify and remove the highly correlated independent variables (greater than 0.7 and less than -0.7) and we end up with 55 features for training the different models; the heat map for the correlation matrix is found in (S19 Fig).