## 2 Materials and Methods
### Dataset Description
This process is necessary to clear the waste products that arise from the destruction of aged or abnormal red blood cells [28]. The normal range of bilirubin for adults is in the range of 1.2 [mg/dL] [29]. High bilirubin may indicate anemia, cirrhosis, a reaction to a blood transfusion, Gilbert syndrome, viral hepatitis, reaction to drugs, alcoholic liver disease, and gallstones. The cholesterol (CHOL) level is one of the parameters measured in blood samples [30]. All the CHOL has been created in the liver that the patient's body needs. However, additional CHOL arrives from foods the patient consumes. The normal level of total CHOL is less than 200 [mg/dL] (5.17 [mmol/L]). The borderline high level of total CHOL is in the range of 200-230 [mg/dL] (5.17-6.18 [mmol/L]). All values higher than 240 [mg/dL] (6.21 [mmol/L]) are considered high total CHOL values [31]. The creatinine (CREA) [32] number obtained from blood sample analysis indicates how well the patients' kidneys are working. The normal range of CREA is between 0.7 to 1.3 [mg/dL] for men and 0.6 to 1.1 [mg/dL] for women [33]. The values above predefined ranges for men and women may indicate a blocked urinary tract, kidney problems (damage, failure, infection, reduced blood flow), loss of body fluid, and muscle problems. The gamma-glutamyltransferase (GGT) [34] is an enzyme that is mainly found in a patient's liver. By measuring the GGT concentration in a patient's blood its activity is being measured. The normal range of GGT in the blood is 5-40 [U/L], according to [35]. Since higher levels of GGT in a blood sample can indicate liver damage/disease the GGT is used as a diagnostic marker for liver disease. The latent elevations of GGT can be recorded in patients with chronic viral hepatitis infections which often take 12 months or more to present. The total protein (PROT) [36] is the parameter that represents the total amount of two classes of proteins found in blood and these are ALB and globulins. The globulins are a group of proteins in the blood and are made in the liver by the patient's immune system. The normal range of PROT is 60 to 83 [g/L] [37]. The higher than normal levels of PROT may indicate chronic inflammation or infection (HIV, hepatitis B/C), multiple myeloma, and Waldenstrom disease. However, lower-than-normal levels of PRT may indicate bleeding, burns, glomerulonephritis, liver disease, malabsorption, malnutrition, nephrotic syndrome, and protein-losing enteropathy. The initial statistical analysis of the dataset is shown in Table 1.  
The correlation analysis can be used as an initial indicator of how well are variable correlated. If the variables do not have any correlation with each other it is hardly feasible to assume that the ML model will be able to establish the correlation between investigated variables. The correlation can be described as the connection between the input and output variables. In this case, [PERSON]'s correlation analysis was used and the correlation value can be in the range from \(-1.0\) up to \(1.0\). If the correlation value is equal to \(-1.0\) this means that if the value of the input variable rises the value of the output variable would drop and vice versa. In case [PERSON]'s correlation is equal to \(1.0\) this means that if the value of the input variable increases the value of the output variable will also increase. The best correlation ranges are from \(-1.0\) to \(-0.5\) and from \(0.5\) to \(1.0\). The worst correlation range is from \(-0.5\) to \(0.5\). Possibly the worst correlation value is \(0\) which means that if the value of the input variable increases/decreases it will absolutely not have any effect on the output variable value. The result of [PERSON]'s correlation analysis performed on the original dataset is shown in Figure 2.