Characteristic | N | Cases | Controls | Combined | P-value |
---|---|---|---|---|---|
 |  | (n = 120) | (n = 120) | (n = 240) |  |
Agec (IQR) | 240 | 59.3 (53.2, 65.7) | 59.3 (52.7, 65.7) | 59.3 (53.2, 65.7) | 0.885a |
Female gender (%) | 240 | 53 (44) | 56 (47) | 109 (45) | 0.791b |
Smoking (%) | 231 | Â | Â | Â | 0.505b |
Never | Â | 40 (34) | 33 (29) | 73 (32) | Â |
Former | Â | 44 (38) | 40 (35) | 84 (36) | Â |
Current | Â | 33 (28) | 41 (36) | 74 (32) | Â |
Diabetes (%) | 240 | 31 (26) | 47 (39) | 78 (32) | 0.045b |
Summer season (%) | 240 | 34 (28) | 35 (29) | 69 (29) | 1b |
Day length hours (IQR)c | 240 | 12.0 (10.6, 13.6) | 12.0 (10.6, 13.5) | 12.0 (10.6, 13.6) | 0.655a |
APACHE II Score (IQR)c | 240 | 28 (23, 32.2) | 28 (23, 32.2) | 28 (23, 32.2) | NA |
Number of non-pulmonary organ failures (%) | 240 | Â | Â | Â | 0.753a |
0 | Â | 15 (12) | 24 (20) | 39 (16) | Â |
1 | Â | 60 (50) | 45 (38) | 105 (44) | Â |
2 | Â | 39 (32) | 39 (32) | 78 (32) | Â |
3 | Â | 4 (3) | 9 (8) | 13 (5) | Â |
4 | Â | 2 (2) | 3 (2) | 5 (2) | Â |
Days of ICU stay (IQR) | 240 | 9 (6,15) | 6 (4,10) | 7 (4,14) | 0.008a |
Hospital mortality (%) | 240 | 30 (25) | 31 (26) | 61 (25) | 1b |
One-year mortality (%) | 240 | 66 (55) | 71 (59) | 137 (57) | 0.614b |
Risk factors for ALI/ARDS | 240 | Â | Â | Â | < 0.001b |
Non-pulmonary sepsis | Â | 55 (46) | 70 (60) | 125 (53) | Â |
Pneumonia | Â | 39 (33) | 22 (19) | 61 (26) | Â |
Aspiration | Â | 24 (20) | 8 (7) | 32 (14) | Â |
Other or Noned | Â | 1 (1) | 16 (14) | 17 (16) | Â |
Patients on ventilator | Â | 89 (74) | 71 (59) | 160 (67) | 0.016b |
25-OHD (nmol/L) (IQR) | 239 | 45.8 (29.9, 60.8) | 39.0 (25.0, 56.9) | 43.2 (27.6, 58.8) | 0.123a |
Vitamin D status (%) | 239 | Â | Â | Â | 0.358b |
Deficiency (< 50 nmol/L) | Â | 72 (60) | 82 (69) | 154 (64) | Â |
Insufficiency (50 to 75 nmol/L) | Â | 32 (27) | 26 (22) | 58 (24) | Â |
Sufficiency (> 75 nmol/L) | Â | 16 (13) | 11 (9) | 27 (11) | Â |