Risk factors

No. of patients

% percentage

Recurrent patients

p value

- Age

・ <40

・ 40 - 50

・ 50 - 60

・ >60

4

8

20

50

4.9

9.7

24.4

61

-

-

-

6

0.246

- Diabetes mellitus (D.M)

20

24.4

4

0.027*

- Hypertension

28

34.1

6

0.021*

- Liver disease

4

4.9

-

- Prothrombin time > 14 sec.

6

7.3

2

0.025*

- Prothrombin Conc. <70%

6

7.3

2

0.029*

- Hb level < 10 mg/Dl

6

7.3

-

- Internal architecture of SDH:

・ Homogenous

・ Laminar

・ Separated

・ Trabecular

42

14

10

16

51.2

17.1

12.2

19.5

-

-

2

4

0.044*

0.025*

- SD hematoma thickness:

・ 10 - 20 mm

・ >20 mm

14

68

17.1

82.9

-

6

0.034*

- Number of burr-holes:

・ 1 burr-hole

・ 2 burr holes

10

72

12.2

87.8

-

6

0.633

- Position of drain:

・ Subgleal (Sg)

・ Subdural (Sd)

62

20

75.6

24.4

4

2

0.599

- Duration of drainage:

・ Less than 3 days

・ 3 days or more

28

54

34.1

65.9

-

6

0.052

- Amount of drainage:

・ Less than 100 cc

・ 100cc-

・ 200cc-

・ More than 300 cc

2

36

32

12

2.4

43.9

39

14.6

-

4

2

-

0.821

0.596

- Postoperative residual hematoma on follow up CT Brain

9

10.9

4

0.005*