Table 5.

Variables selection in TWIST system application. In yellow variables selected in each round of TWIST applications; in purple variables selected in at least 10 TWIST applications; in green variables selected by LDA.

Num	INPUT VARIABLES	LDA	Tw1	Tw2	Tw3	Tw4	Tw5	Tw6	Tw7	Tw8	Tw9	Tw10	Tw11	SUM	Euristic
1	male													3
2	female													11
3	Age													10
4	Bleeding in hospital													11
5	previous bleeding													1
6	peptic ulcer													1
7	gastric surgery													1
8	hypertension													1
9	Obstructive lung disease													11
10	kidney failure													0
11	dialisis													8
12	ischemic hearth disease													1
13	cardiac dilatation													8
14	cardiac failure													7
15	diabetes													0
16	cancer													11
17	cancer site													10
18	leukemia													9
19	liver cirrosis													11
20	cerebro vascular disease													2
21	no concomitant diseases													1
22	aspirin													5
23	ticlopidine													11
24	clopidogrel													10
25	celecoxib													9
26	rofecoxib													10
27	NSAIDs													11
28	Anticoagulant agents													1
29	calcium antagonists													1
30	nitroderivates													10
31	heparine													6
32	corticosteroids													3
33	antidepressant													4
34	syncope													4
35	hematemesis													1
36	melena													1
37	black vomiting													11
38	red blood vomiting													11
39	sistolic blood pressure													11
40	diastolic blood pressure													5
41	heart rate													2
42	presence of blood in rectum													11
43	black blood													11
44	red blood vomiting													2
45	nasogastric intubation													0
46	red blood from gastric tube													7
47	black blood from gastric tube													9
48	solid material from gastric tube													3
49	time from symptoms and hospital													0
50	hemoglobin value													9
	Total variables selected	10	26	25	25	24	24	28	30	34	28	19	27		17