Optimization of Tree-Based Machine Learning Models to Predict the Length of Hospital Stay Using Genetic Algorithm

Table 4

Correlation between independent variables and LOS.

No.	Variable	Correlation		< 0.05
1	Age	−0.06	0.4032
2	Medical advice number	0.46	0.0001	<0.05
3	Sex_F	0.02	0.7823
4	Marital status_married	−0.04	0.5808
5	Main insurance type_employee HI	0.20	0.0066	<0.05
6	Main insurance type_occupational SSI	0.08	0.2579
7	Main insurance type_ordinary SSI	0.02	0.7514
8	Main insurance type_special SSI	−0.05	0.4677
9	Main insurance type_without insurance	−0.16	0.0291	<0.05
10	Physician expertise level_general practitioner	0.02	0.7447
11	Physician expertise level_specialist	−0.07	0.3696
12	Physician expertise level_subspecialty physician	0.17	0.0206	<0.05