Table 2. Overall statistical description for categorical variables (n = 4904).

Variables	Sub-variables	Statistics
Gender	Male	2242 (45.7%)
	Female	2662 (54.3%)
Alcohol	Yes	1281 (26.1%)
	No	3619 (73.8%)
Allergy	Yes	259 (5.3%)
	No	3726 (76%)
Endoscopy	EGD	3902 (79.6%)
	Colonoscopy	980 (20%)
	EGD+colonoscopy	19 (0.4%)
ASA scores	I	1189 (24.2%)
	II	2364 (48.2%)
	III	756 (15.4%)
	IV	63 (1.3%)
Lung disease	No	4518 (92.5%)
	COPD	45 (0.9%)
	Chronic bronchitis	153 (3.1%)
	Pulmonary emphysema	27 (0.6%)
	Asthma	94 (1.9%)
	Others	45 (0.9%)
Other preexisting diseases	No	2103 (42.9%)
	Hypertension	615 (12.5%)
	Diabetes	165 (3.4%)
	CHF	108 (2.2%)
	Stroke	50 (1%)
	Liver cirrhosis	79 (1.6%)
	GI diseases	728 (14.8%)
	Cancer	68 (1.4%)
	Heart diseases	182 (3.7%)

CHF Chronic Heart Failure, COPD Chronic Obstructive Pulmonary Disease, EGD Esophagogastroduodenoscopy, GI gastrointestinal.

n (%) are presented in the table.