CRP= C reactive protein; WBC = White Blood Cells; RBC = Red Blood Cells; HGB = Hemoglobin; PLT = Platelets; %Neu = Neutrophils (percentage); %Lymph = Lymphocytes (percentage); %Mon = Monocytes (percentage); %Eos = Eosinophils (percentage); #Eos = Eosinophils (number); %Bas = Basophils (percentage); #Bas = Basophils (number);#Neu = Neutrophils (number); #Lymph = Lymphocytes (number); #Mon = Monocytes (number); HCT = Hematocrit; MCV = Mean Corpuscular Volume; MCHC = Mean Corpuscular Hemoglobin Concentration; MCH = Mean Corpuscular Hemoglobin; RDW-SD = Red Cell Distribution Width-Standard Deviation; RDW-CV = Red Cell Distribution Width-Coefficient of Variation; PDW = Platelet Distribution Width; MPV = Mean Platelet Volume; PCT = Plateletcrit; P-LCR = Platelet Large Cell Ratio.
Predictor variable screening results
Among the baseline indicators in the training cohort, univariate logistic regression showed age, White Blood Cells (WBC), Red Blood Cells (RBC), Neutrophils percentage (%Neu), Neutrophils number (#Neu), Lymphocytes percentage (%Lymph), Monocytes percentage (%Mon), Red Cell Distribution Width-Standard Deviation (RDW-SD), Platelet Distribution Width (PDW), Mean Platelet Volume (MPV), Platelet Large Cell Ratio (P-LCR), CRP natural log-transformed value (InCRP), Eosinophils (percentage) (%Eos), Basophils percentage (%Bas), Basophils number (#Bas) as possible predictors(p < 0.1), further multivariate logistic regression showed age, CRP natural log-transformed value (InCRP), Neutrophils percentage (%Neu), and Monocytes percentage (%Mon) as independent predictors (p < 0.05)( TABLE 2). Three predictors with non-zero coefficients were obtained by Lasso regression (screening lambda by 10-fold cross-validation, based on lambda.1se, i.e., the maximum lambda corresponding to an error mean within one standard deviation of the minimum): age, CRP natural log-transformed value (InCRP), Monocytes percentage (%Mon) (FIGURE 2). To reduce irrelevant and redundant information, the variables selected by both screening methods were taken as the final selected predictor variables: age, natural log-transformed value (InCRP), and Monocytes percentage (%Mon).