Table 1 Characteristics of participants for model development and validation
|  | Model development (N = 1015) | Model validation (N = 507) |
|---|---|---|
Mean (SD) age, years | 37.8 (10.3) | 37.1 (10.2) |
Female, n(%) | 392 (38.6%) | 221 (43.6%) |
Mean (SD) BMI, kg/m2 | 22.1 (3.2) | 21.8 (3.2) |
Education | ||
 Illiteracy, n(%) | 50 (4.9%) | 17 (3.4%) |
 Primary school, n(%) | 97 (9.6%) | 71 (14.0%) |
 Junior middle school, n(%) | 445 (44.0%) | 225 (44.4%) |
 Senior middle school, n(%) | 252 (24.9%) | 118 (23.3%) |
 University or higher, n(%) | 168 (16.6%) | 76 (15.0%) |
Family annual income | ||
 0–30 000 Yuan | 416 (41.1%) | 198 (39.1%) |
 30 000–80 000 Yuan | 327 (32.3%) | 185 (36.5%) |
 80 000–120 000 Yuan | 149 (14.7%) | 75 (14.8%) |
 120 000–300 000 Yuan | 66 (6.5%) | 33 (6.5%) |
 300 000 Yuan and above | 36 (3.6%) | 10 (2.0%) |
 Current smoker, n(%) | 234 (23.2%) | 101 (20.0%) |
 Current alcohol drinker, n(%) | 169 (16.8%) | 70 (13.9%) |
 Self-reported pharyngitis, n(%) | 228 (22.5%) | 94 (18.6%) |
 Current use of psychotropic medicine, n(%) | 15 (1.5%) | 4 (0.8%) |
 Mean (SD) self-evaluated tolerancea | 3.1 (0.9) | 3.1 (0.9) |
 Mean (SD) expected level of discomforta | 3.2 (0.9) | 3.3 (0.9) |
 Mean (SD) level of anxiety before endoscopya | 2.7 (1.2) | 2.7 (1.2) |
Pharyngeal sensitivity | ||
 Absent, n(%) | 24 (2.8%) | 8 (1.8%) |
 Attenuated, n(%) | 75 (8.6%) | 21 (4.8%) |
 Normal, n(%) | 770 (88.6%) | 406 (93.3%) |
Mallampati classification | ||
 Class I, n(%) | 231 (26.6%) | 121 (27.8%) |
 Class II, n(%) | 301 (34.7%) | 145 (33.3%) |
 Class III, n(%) | 164 (18.9%) | 78 (17.9%) |
 Class IV, n(%) | 171 (19.7%) | 92 (21.1%) |
Indication of endoscopy | ||
 Healthy physical examination | 87 (8.6%) | 42 (8.3%) |
 Suspected gastrointestinal disease | 587 (57.8%) | 288 (56.8%) |
 Gastrointestinal tumor warning symptoms | 124 (12.2%) | 77 (15.2%) |
 Various treatments under endoscopy | 167 (16.5%) | 83 (16.4%) |
 Lesions with regular follow-up | 50 (4.9%) | 17 (3.4%) |
Endoscopy findings | ||
 Chronic gastritis | 980 (96.6%) | 479 (94.5%) |
 Peptic ulcer | 95 (9.34%) | 53 (10.5%) |
 Gastric polyps | 147 (14.5%) | 76 (15.0%) |
 Esophagus-gastric varices | 86 (8.5%) | 38 (7.4%) |
 Gastric cancer | 45 (4.4%) | 20 (4.0%) |
 Portal hypertensive gastropathy | 31 (3.1%) | 16 (3.2%) |
 Esophagus-gastric submucosal tumor | 99 (9.7%) | 57 (11.2%) |