Table 4 Results of risk factor analysis of pneumothorax

Family history of pneumothorax

19.84

2.98

132.12

0.002

History of pneumothorax

2.44

0.62

9.64

0.20

Maximal cyst size

0.98

0.94

1.03

0.49

Cyst number

 ≤ 50

1.00

 50–100

0.66

0.15

2.97

0.67

 ≥ 100

0.97

0.08

11.24

0.89

Cyst shape

 Round/ovoid

1.00

 Lentiform

0.79

0.14

4.50

0.79

 Irregular

0.11

0.01

2.67

0.18

 Septated

1.90

0.11

32.66

0.66

Fissural cyst

2.92

0.07

127.04

0.58

Encircling bronchovascular bundle (air-cuff sign)

1.26

0.34

4.63

0.73

Location of largest cyst (subpleural)

1.20

0.25

5.83

0.82