Table 1.

Demographic data of patients treated with warfarin.

Variables	Patients without GIB* (n = 365)	Patients with GIB* (n = 36)	P value
Age (year)	64.1 ± 17.0	74.3 ± 12.3	<0.001
Male	215	19	0.5
Smoking	101 (27.6%)	10 (27.7)	1.0
Alcohol	73 (20.0%)	6 (16.6%)	0.6
Indications for warfarin
Deep vein thrombosis	63 (17.2%)	8 (22.2%)	0.5
Pulmonary embolism	28 (7.6%)	3 (8.3%)	0.9
Valvular replacement	138 (37.8%)	10 (27.7%)	0.2
Atrial fibrillation	81 (22.1%)	8 (22.2%)	1.00
Others	55 (15.0%)	7 (19.4%)	0.5
Platelet count (K/cumm)	201.6 ± 139.2	206.8 ± 144.5	0.9
Mean INR* value	1.8 ± 1.2	2.2 ± 1.7	0.01
History of GIB†	12 (3.2%)	5 (13.8%)	0.003
Comorbidity
Hypertension	200 (54.8%)	22 (61.1%)	0.5
Cardiovascular disease	62 (16.9%)	6 (16.6%)	1.0
Pulmonary disease	32 (8.7%)	6 (16.6%)	0.1
Cirrhosis	1 (0.2%)	3 (8.3%)	<0.001
Renal insufficiency	27 (7.3%)	4 (11.1%)	0.4
Malignancy	38 (10.4%)	5 (13.9%)	0.6
Septic shock	2 (0.5%)	3 (8.3%)	<0.001
Concomitant medication
NSAID‡	6 (1.6%)	2 (5.5%)	0.1
Aspirin	46 (12.6%)	4 (11.1%)	0.8
Clopidogrel	30 (8.2%)	1 (2.7%)	0.2
Dipyridamole	22 (6.0%)	5 (13.8%)	0.07
Steroids	25 (6.8%)	4 (11.1%)	0.3

*INR: international normalization ratio.

^†GIB: gastrointestinal bleeding.

^‡NSAID: nonsteroidal anti-inflammatory drug.