gastroscopy ; 0:absent, 1:present
group ; 0 : P group, 1: S group, 2: A group, 3: K group
sex; 0:Male 1: Female
MALLAMPATI ; Mallampati score 1 to 4, NA : missing
Hypertension ; 0:absent, 1:present
Ischemic
cardiopathy; Should be one column: Ischemic cardiopathy;  0:absent, 1:present
COPD; Chronic obstructive pulmonary disease; 0:absent, 1:present
Obstructive sleep apnea syndrome;  0:absent, 1:present
Tobacco use ; 0:absent, 1:present
Biopsy ; 0:absent, 1:present
Polypectomy ; 0:absent, 1:present