Table 4 Multivariate Poisson regression analysis of difficult-to-transfer cases in all patients

Year

 2018

Reference

 2019

0.93

0.90

 − 

0.95

 < 0.001

 2020

1.24

1.21

 − 

1.27

 < 0.001

Month

 June

Reference

 January

1.93

1.84

 − 

2.02

 < 0.001

 February

1.85

1.76

 − 

1.94

 < 0.001

 March

1.49

1.41

 − 

1.57

 < 0.001

 April

1.59

1.51

 − 

1.67

 < 0.001

 May

1.39

1.32

 − 

1.47

 < 0.001

 July

1.14

1.08

 − 

1.20

 < 0.001

 August

1.41

1.34

 − 

1.49

 < 0.001

 September

1.20

1.14

 − 

1.27

 < 0.001

 October

1.12

1.06

 − 

1.18

 < 0.001

 November

1.28

1.21

 − 

1.35

 < 0.001

 December

1.52

1.45

 − 

1.60

 < 0.001

Time of transportation

 9 am to 10 am

Reference

 0 am to 1 am

6.44

5.91

 − 

7.02

 < 0.001

 1 am to 2 am

7.42

6.80

 − 

8.08

 < 0.001

 2 am to 3 am

7.95

7.29

 − 

8.67

 < 0.001

 3 am to 4 am

7.66

7.02

 − 

8.37

 < 0.001

 4 am to 5 am

7.61

6.96

 − 

8.31

 < 0.001

 5 am to 6 am

6.80

6.21

 − 

7.44

 < 0.001

 6 am to 7 am

5.49

5.01

 − 

6.00

 < 0.001

 7 am to 8 am

3.98

3.63

 − 

4.36

 < 0.001

 8 am to 9 am

2.16

1.97

 − 

2.38

 < 0.001

 10 am to 11 am

1.25

1.13

 − 

1.38

 < 0.001

 11 am to 12 pm

1.58

1.44

 − 

1.75

 < 0.001

 12 pm to 1 pm

1.92

1.75

 − 

2.11

 < 0.001

 1 pm to 2 pm

2.18

1.98

 − 

2.39

 < 0.001

 2 pm to 3 pm

2.21

2.01

 − 

2.42

 < 0.001

 3 pm to 4 pm

2.41

2.19

 − 

2.64

 < 0.001

 4 pm to 5 pm

2.41

2.19

 − 

2.64

 < 0.001

 5 pm to 6 pm

3.08

2.82

 − 

3.37

 < 0.001

 6 pm to 7 pm

3.85

3.54

 − 

4.20

 < 0.001

 7 pm to 8 pm

4.48

4.12

 − 

4.88

 < 0.001

 8 pm to 9 pm

4.81

4.42

 − 

5.23

 < 0.001

 9 pm to 10 pm

4.86

4.46

 − 

5.29

 < 0.001

 10 pm to 11 pm

5.25

4.82

 − 

5.72

 < 0.001

 11 pm to 0 am

5.76

5.29

 − 

6.28

 < 0.001

Day of week

 Friday

Reference

 Monday

1.11

1.07

 − 

1.15

 < 0.001

 Tuesday

1.08

1.04

 − 

1.12

 < 0.001

 Wednesday

1.09

1.05

 − 

1.13

 < 0.001

 Thursday

1.06

1.02

 − 

1.10

0.004

 Saturday

1.26

1.21

 − 

1.30

 < 0.001

 Sunday

1.38

1.34

 − 

1.43

 < 0.001

 Adults, ≥ 15 years

Reference

 Children

0.35

0.33

 − 

0.37

 < 0.001

 Suspected COVID-19

2.50

2.27

 − 

2.75

 < 0.001