Table 4 Comparison of the CS rates of each group of the Robson classification by hospital peer-group in Iran, 21 March 2019–21 March 2021

1

28.9 ± 9.7 ^a

50.7 ± 18.4 ^b

26.8 ± 11.6 ^a

0.4

<  0.001

2

46.7 ± 13.2 ^a

83.1 ± 14.6 ^b

53.5 ± 22 ^a

0.4

<  0.001

3

6.4 ± 2.6 ^a

12.7 ± 8.9 ^b

4.8 ± 3.1 ^a

0.3

<  0.001

4

19.5 ± 9 ^a

48.2 ± 19.5 ^b

26.8 ± 11.6 ^a

0.4

<  0.001

5

97.7 ± 2.5 ^a

99.5 ± 0.3 ^b

98.7 ± 1.4 ^b

0.1

<  0.001

6

96.3 ± 3.6 ^a

98.8 ± 0.9 ^b

97.3 ± 2.6

0.1

<  0.001

7

91.8 ± 4.2 ^a

95.2 ± 3.7 ^b

93.5 ± 4.4

0.1

0.001

8

87 ± 6.6 ^a

96.6 ± 2.4 ^b

89.4 ± 7.1 ^a

0.3

<  0.001

9

100 ^a

100 ^a

100 ^a

0

1

10

51 ± 9.8 ^a

70.3 ± 11.6 ^b

49.6 ± 11 ^a

0.4

<  0.001