Table 2 Z-test results of four continuous variables

Patient age (years)

45.311 ± 19.423

49.136 ± 21.218

25.238

P = 0.001

Hospitalization days (day)

9.512 ± 8.943

15.075 ± 29.476

38.741

P = 0.001

Hospitalization times

2.163 ± 2.700

1.834 ± 4.503

4.570

P = 0.033

Blood transfusion volume (ml)

37.744 ± 253.252

171.393 ± 1029.725

18.886

P = 0.001

Hospitalization expenses (CNY)

1.995 ± 3.365

2.612 ± 5.945

9.791

P = 0.002