|  |  | Study Group N= 69 | Control Group N= 67 | P-value |
---|---|---|---|---|---|
Patient | age | years, mean (range) | 57 (19 to 81) | 62 (18 to 84) | 0.57 |
characteristics | gender | male | 68.1% | 64.2% | 0.72 |
 | education | university | 7.2% | 11.9% | 0.07 |
 |  | college | 40.6% | 19.4% |  |
 |  | high school | 42.0% | 55.2% |  |
 |  | other | 10.1% | 13.4% |  |
 | smoking | daily smoking | 20.3% | 23.9% | 0.68 |
 |  | number of cigarettes per day when smoking | 17.4 | 11.8 | 0.14 |
 | alcohol | regular use | 46.4% | 40.3% | 0.49 |
 |  | number of units/week when regularly use | 6.7 | 5.8 | 0.65 |
 | living single at home | yes | 18.8% | 28.4% |  |
 | professionally active | yes | 46.4% | 31.3% | 0.01 |
 | kids | yes | 73.9% | 73.1 | 0.92 |
Chronic pathology | ≥ 1 Comorbidity | yes | 68.1% | 75.8% | 0.32 |
Acute illness | TISS 28 | mean (range) | 24.5 (9 to 40) | 24.5 (11 to 43) | 0.74 |
 | SOFA score first 24 hrs | mean (range) | 7.2 (1 to 14) | 7.0 (2 to 15) | 0.65 |
 | SAPS 3 score | mean (range) | 42.5 (0 to 78) | 42.1 (0 to 78) | 0.89 |
 | admission | surgery | 69.6% | 79.1% | 0.20 |
 |  | internal medicine | 30.4% | 20.9% |  |
 |  | emergency surgery versus scheduled research | 21.6% | 29.7% | 0.30 |
 | first time intensive care | yes | 65.2% | 44.8% | 0.02 |
 | Maximal RIFLE | No acute kidney injury | 3.1% | 9.5% | 0.22 |
 | score during study | risk | 9.2% | 3.2% |  |
 |  | injury | 20.0% | 15.9% |  |
 |  | failure | 67.7% | 71.4% |  |
 | SLEDD necessity | Number of patients | 4 | 5 | 0.52 |
 | length in study | mean hours of observation per patient (SD) | 42.8 (25.7) | 32.6 (25.7) | 0.02 |
Environment | intensive care unit | study unit 1 | 21.7% | 17.9% | 0.57 |
 |  | study unit 2 | 21.7% | 26.9% |  |
 |  | study unit 3 | 29.0% | 20.9, % |  |
 |  | study unit 4 | 27.5% | 34.3% |  |
 | visible clock | yes | 95.7% | 89.6% | 0.17 |
 | visible daylight | yes | 60.9% | 67.2% | 0.45 |
 | isolation | yes | 2.9% | 6.0% | 0.38 |
 | no visit | yes | 0.0% | 4.5% | 0.12 |
 | room | open | 39.1% | 56.7% | 0.12 |
 |  | separated by walls, open end | 18.8% | 11.9% |  |
 |  | closed box | 42.0% | 31.3% |  |