Results of multiple univariate regression analysis (unadjusted) for the variables in the left column
| Variables | AMS, n (%) | Crude OR (95% CI) | p Value |
| SpO2 (%) | |||
| ≥90 | 32 (33) | 1 (ref) | |
| 86–89 | 65 (40) | 0.986 (0.647 to 1.545) | 0.069 |
| ≤85 | 76 (62) | 2.630 (2.156 to 3.274) | <0.001 |
| Hb (g/dl) | |||
| ≤16 | 142 (46) | 1 (ref) | |
| >16 | 31 (42) | 0.745 (0.504 to 0.762) | 0.238 |
| PAPm (mm Hg) | |||
| ≤20 | 164 (45) | 1 (ref) | |
| >20 | 9 (45) | 0.645 (0.446 to 0.672) | 0.164 |
| VC | |||
| Normal | 168 (46) | 1 (ref) | |
| Less by ≥2 SD | 5 (39) | 0.211 (0.096 to 0.747) | 0.770 |
| Smoking | |||
| No smoking | 102 (51) | 1 (ref) | |
| <1 pack/day | 16 (49) | 0.860 (0.674 to 0.901) | 0.755 |
| 1 pack/day | 30 (37) | 0.786 (0.652 to 0.810) | 0.035 |
| >1 pack/day | 25 (37) | 0.627 (0.335 to 0.856) | 0.039 |
| Smoking history | |||
| No smoking | 102 (51) | 1 (ref) | |
| Short term | 17 (40) | 0.864 (0.520 to 0.978) | 0.465 |
| Medium term | 25 (39) | 0.818 (0.465 to 1.075) | 0.044 |
| Long term | 29 (38) | 0.654 (0.358 to 0.861) | 0.027 |