Table 4 Known-group-validity: clinical characteristics in relation to mean change scores from baseline to follow-up

Duration of preoperative otorrhea

< 33 months, Mean (SD)

n = 14

3.92 (3.73)

12.15 (6.53)

4.29 (2.55)

20.23 (8.73)

≥ 33 months Mean (SD)

n = 15

0.60 (3.44)

7.33 (8.38)

1.79 (4.42)

10.21 (13.64)

p

0.02

0.11

0.08

0.03

Primary versus revision surgery

Primary

n = 12

2.64 (3.41)

9.55 (7.45)

3.50 (3.61)

15.45 (10.33)

Revision

n = 17

1.82 (4.25)

9.56 (8.30)

2.69 (3.96)

14.75 (14.00)

p

0.60

0.99

0.58

0.88

Amount of previous operations

0 operations

n = 12

2.64 (3.41)

9.55 (7.45)

3.50 (3.61)

15.45 (10.33)

≥ 1 operations

n = 17

1.82 (4.25)

9.56 (8.30)

2.69 (3.96)

14.75 (14.00)

p

0.60

0.99

0.58

0.88

Postoperative dry ears

Yes

n = 24

2.65 (3.71)

11.65 (6.67)

3.79 (3.43)

18.00 (10.16)

No

n = 5

−0.20 (4.27)

0.00 (5.48)

−1.50 (2.38)

−2.00 (11.17)

p

0.14

< 0.01

< 0.01

< 0.01

Postoperative improved hearing

Yes

n = 21

1.86 (4.56)

15.43 (5.53)

5.00 (1.69)

22.14 (5.11)

No

n = 8

2.24 (3.77)

7.62 (7.59)

2.25 (4.10)

12.55 (13.33)

p

0.83

0.02

0.02

0.01

Postoperative decreased hearing

Yes

n = 5

2.00 (2.83)

7.00 (5.57)

1.20 (3.56)

8.20 (13.31)

No

n = 24

2.17 (4.14)

10.13 (8.24)

3.43 (3.76)

16.59 (11.98)

p

0.93

0.43

0.24

0.17