Table 1 Patient characteristics
|  | All (n = 114) | Radiopaque (n = 28) | Radiolucent (n = 86) | P-value |
|---|---|---|---|---|
Age, years | ||||
|  | 65 (52–74) | 66 (52–75) | 62 (54–68) | 0.65 |
Sex | ||||
 Female | 43 (38%) | 10 (36%) | 33 (38%) | 0.98 |
 Male | 71 (62%) | 18 (64%) | 53 (62%) | |
Witnessed choking | ||||
 Yes | 19 (17%) | 17 (61%) | 2 (2%) |  < 0.001* |
 No | 95 (83%) | 11 (39%) | 84 (93%) | |
Length of disease course, days | ||||
|  | 30 (9–150) | 7 (1–30) | 60 (14–150) |  < 0.001* |
  < 60 | 65 (57%) | 23 (82%) | 42 (49%) | 0.004* |
  ≥ 60 | 49 (43%) | 5 (18%) | 44 (51%) | |
Experience in ICU | ||||
 Yes | 12 (11%) | 0 (0%) | 12 (14%) | 0.04* |
 No | 102 (89%) | 28 (100%) | 74 (86%) | |
Symptoms | ||||
 Coughing | 103 (90%) | 25 (89%) | 78 (91%) | 1 |
 Purulent sputum | 84 (74%) | 21 (75%) | 63 (73%) | 1 |
 Chest tightness | 49 (43%) | 13 (46%) | 36 (42%) | 0.84 |
 Hemoptysis | 25 (22%) | 10 (36%) | 15 (17%) | 0.08 |
 Fever | 9 (8%) | 0 (0%) | 9 (10%) | 0.11 |
 Dyspnea | 6 (5%) | 1 (4%) | 5 (6%) | 1 |
 Chest pain | 5 (4%) | 0 (0%) | 5 (6%) | 0.33 |
 Disturbance of consciousness | 1 (1%) | 1 (4%) | 0 (0%) | 0.25 |
Physical examination | ||||
 Rales | 24 (21%) | 4 (14%) | 20 (23%) | 0.46 |
 Wheezing | 6 (5%) | 1 (4%) | 5 (6%) | 1 |
Complications | ||||
 Chronic diseases requiring daily medication | 59 (52%) | 17 (61%) | 42 (49%) | 0.38 |
 Chronic respiratory disease | 30 (26%) | 8 (29%) | 22 (26%) | 0.95 |
 Post-stroke dysphagia | 18 (16%) | 4 (14%) | 14 (16%) | 1 |
 Alzheimer's disease | 3 (3%) | 2 (7%) | 1 (1%) | 0.15 |
 Throat surgery/diseases | 2 (2%) | 1 (4%) | 1 (1%) | 0.43 |
 Dental operation | 1 (1%) | 1 (4%) | 0 (0%) | 0.25 |
Misdiagnosis | ||||
 Pneumonia | 64 (56%) | 7 (25%) | 57 (66%) |  < 0.001* |
 Cancer | 5 (4%) | 0 (0%) | 5 (6%) | 0.33 |