Table 1. Baseline and hospitalization characteristics of ICU admissions, 2001–2008.
| Variables | Groups per admission period | |||||||||
| August 2001–April2003 (n = 1544) | May 2003–January2005 (n = 2070) | February 2005–October2006 (m = 2504) | November 2006–August2008 (n = 2798) | P value | ||||||
| Unit of discharge, n (%) | ||||||||||
| Medical | 1109 (71.8) | 1255 (60.6) | 1557 (62.2) | 1676 (59.9) | <.001 | |||||
| Surgical/Trauma | 435 (28.2) | 815 (39.4) | 947 (37.8) | 1122 (40.1) | ||||||
| Male gender, n (%) | 778 (50.6) | 991 (48.1) | 1241 (49.6) | 1368 (48.9) | .49 | |||||
| Age, years (±SD) | 78.09±7.56 | 78.23±7.73 | 78.25±7.85 | 78.91±8.11 | .001 | |||||
| Married, n (%) | 748 (48.4) | 1001 (48.4) | 1162 (46.4) | 1282 (45.8) | .19 | |||||
| Co morbidities, n (%) | ||||||||||
| Elixhauser | 5.97±7.20 | 6.97±7.45 | 7.53±8.00 | 6.78±7.94 | <.001 | |||||
| Diabetes uncomplicated | 257 (16.7) | 316 (15.3) | 604 (24.2) | 687 (24.6) | <.001 | |||||
| Diabetes complicated | 67 (4.3) | 62 (3.0) | 180 (7.2) | 156 (5.6) | <.001 | |||||
| Congestive heart failure | 455 (29.5) | 734 (35.5) | 1000 (40.0) | 926 (33.1) | <.001 | |||||
| Alcohol abuse | 20 (1.3) | 44 (2.1) | 62 (2.5) | 61 (2.2) | .08 | |||||
| Cardiac arrhythmias | 447 (29.0) | 653 (31.6) | 951 (38.0) | 1049 (37.5) | <.001 | |||||
| Valvular disease | 136 (8.8) | 223 (10.8) | 342 (13.7) | 320 (11.5) | <.001 | |||||
| Hypertension | 473 (30.7) | 656 (31.8) | 1186 (47.4) | 1331 (47.6) | <.001 | |||||
| Chronic renal failure | 104 (6.7) | 199 (9.6) | 298 (11.9) | 158 (5.7) | <.001 | |||||
| COPD | 309 (20.0) | 459 (22.2) | 637 (25.5) | 659 (23.6) | .001 | |||||
| Liver failure | 29 (1.9) | 71 (3.4) | 87 (3.5) | 92 (3.3) | .02 | |||||
| Metastatic cancer | 84 (5.4) | 133 (6.4) | 149 (6.0) | 196 (7.0) | .18 | |||||
| Psychosis | 23 (1.5) | 37 (1.8) | 74 (3.0) | 85 (3.0) | .001 | |||||
| Depression | 34 (2.2) | 45 (2.2) | 104 (4.2) | 182 (6.5) | <.001 | |||||
| Drug abuse | 2 (0.1) | 7 (0.3) | 9 (0.4) | 1 (0.0) | <.001 | |||||
| Admission source | ||||||||||
| Emergency Department | 1030 (66.7) | 1488 (71.9) | 1855 (74.1) | 2189 (78.2) | <.001 | |||||
| Other hospital | 236 (15.3) | 291 (14.1) | 293 (11.7) | 310 (11.1) | ||||||
| Other | 278 (18.0) | 291 (14.1) | 356 (14.2) | 299 (10.7) | ||||||
| Proportion of Elderly patients out of all ICU patients (age>65) | ||||||||||
| Total number of admissions | 3410 | 4459 | 5204 | 6437 | <0.001 | |||||
| Proportion of elderly above 65 years of age | 45.5% | 46.3% | 48.4% | 43.1% | 0.014 | |||||
| Primary admission, n (%) | ||||||||||
| Infectious | 105 (6.8) | 241 (11.7) | 376 (15.1) | 382 (13.7) | <.001 | |||||
| Cardiovascular | 394 (25.6) | 465 (22.5) | 476 (19.1) | 543 (19.4) | ||||||
| Respiratory | 236 (15.3) | 280 (13.6) | 363 (14.5) | 378 (13.5) | ||||||
| Cancer | 144 (9.3) | 185 (9.0) | 211 (8.5) | 250 (8.9) | ||||||
| Gastrointestinal | 247 (16.0) | 336 (16.3) | 377 (15.1) | 421 (15.1) | ||||||
| Genitourinary | 53 (3.4) | 65 (3.1) | 73 (2.9) | 85 (3.0) | ||||||
| Trauma | 194 (12.6) | 268 (13.0) | 291 (11.7) | 412 (14.7) | ||||||
| Treatment complication | 62 (4.0) | 108 (5.2) | 138 (5.5) | 113 (4.0) | ||||||
| Other | 106 (6.9) | 118 (5.7) | 191 (7.7) | 211 (7.5) | ||||||
| Acuity score on admission | ||||||||||
| SOFA | 5.82±4.14 | 5.66±3.85 | 5.54±3.79 | 4.87±3.56 | <.001 | |||||
| SAPS 1 | 15.61±5.49 | 14.86±4.87 | 14.88±4.82 | 14.42±4.78 | <.001 | |||||
| Intensity of care | ||||||||||
| Renal replacement therapy during hospitalization | 146 (9.5) | 202 (9.8) | 267 (10.7) | 247 (8.8) | 0.16 | |||||
| Mechanical ventilation during hospitalization | 845 (54.7) | 1185 (57.2) | 1406 (56.2) | 1254 (44.8) | <.001 | |||||
| Use of vasopressors | 513 (33.2%) | 605 (29.2%) | 689 (27.5%) | 627 (22.4%) | <0.001 | |||||
| Don Not Resuscitate (order recorded during ICU admission) | 496 (34.1) | 720 (35.8) | 898 (36.6) | 887 (34.3) | 0.25 | |||||
| MV duration (hours) | 109.17 (32–313.88) | 107.50 (36.0–280.13) | 88.63 (32.25–266.13) | 59.75 (21.55–175.08) | <0.001 | |||||
| ICU LOS (days) | 5.30 (2.44–12.05) | 5.68 (2.99–11.97) | 4.97 (2.74–9.91) | 4.42 (2.44–8.64) | <0.001 | |||||
All elderly admissions (n = 8916).
ICU, intensive care unit; COPD, chronic obstructive pulmonary disease,SOFA, sequential organ failure assessment; SAPS, simplified acute physiology score.