Baseline characteristics of patients admitted to hospital (2000–2011), by the presence of critical illness, and after matching for age, sex and index date, or for propensity score*
| Variable | Acute critical illness | Standardized mean differences§ | ||||
|---|---|---|---|---|---|---|
| Age- and sex-matched | p value‡ | Propensity score–matched | ||||
| No n = 63 148 (%)† | Yes n = 33 613 (%)† | No n = 14 218 (%)† | Yes n = 14 218 (%)† | |||
| Age, yr | 0.001 | |||||
| ≤ 49 | 12 928 (20.5) | 6464 (19.2) | – | 2327 (16.4) | 3104 (21.8) | 0.14 |
| 50–64 | 18 578 (29.4) | 9289 (27.6) | – | 3747 (26.4) | 3486 (24.5) | 0.04 |
| 65+ | 31 642 (50.1) | 17 860 (53.1) | – | 8144 (57.3) | 7628 (53.7) | 0.07 |
| Mean ± SD | 61.9 ± 15.1 | 64.1 ± 15.8 | < 0.001 | 64.1 ± 15.0 | 63.6 ± 17.1 | 0.03 |
| Sex | 0.28 | |||||
| Female | 26 485 (41.9) | 14 218 (42.3) | – | 5972 (42.0) | 5988 (42.1) | 0.002 |
| Male | 36 663 (58.1) | 19 395 (57.7) | – | 8246 (58.0) | 8230 (57.9) | 0.002 |
| Critical illness | ||||||
| Septicemia, septic shock | – | 13 468 (40.1) | – | – | 7746 | – |
| AMI | – | 2324 (6.91) | – | – | 524 | – |
| Stroke | – | 16 921 (50.3) | – | – | 5327 | – |
| Other shock | – | 900 (0.27) | – | – | 621 | – |
| CCI score§ | < 0.001 | |||||
| 0 | 54 664 (86.6) | 6430 (19.1) | – | 5906 (41.5) | 6200 (43.6) | 0.04 |
| 1 | 6671 (10.6) | 17 517 (52.1) | – | 6499 (45.7) | 6156 (43.3) | 0.05 |
| 2 or more | 1813 (2.87) | 9666 (28.8) | – | 1813 (12.8) | 1862 (13.1) | 0.01 |
| Comorbidity | ||||||
| Diabetes | 6778 (10.7) | 8031 (23.9) | < 0.001 | 2403 (16.9) | 2346 (16.5) | 0.01 |
| Cirrhosis | 13 176 (20.9) | 7800 (23.2) | < 0.001 | 3647 (25.7) | 3432 (24.1) | 0.04 |
| Hypertension | 26 883 (42.6) | 22 579 (67.2) | < 0.001 | 7695 (54.1) | 7730 (54.4) | 0.01 |
| Hyperlipidemia | 14 924 (23.6) | 10 510 (31.3) | < 0.001 | 3878 (27.3) | 3897 (27.4) | 0.003 |
| CAD | 13 300 (21.1) | 12 391 (36.9) | < 0.001 | 4235 (29.8) | 4203 (29.6) | 0.01 |
| CHF | 2963 (4.69) | 3951 (11.8) | < 0.001 | 1337 (9.40) | 1312 (9.23) | 0.01 |
| COPD | 10 154 (16.1) | 7532 (22.4) | < 0.001 | 3553 (25.0) | 3340 (23.5) | 0.04 |
| Cancer | 2790 (4.42) | 2144 (6.38) | < 0.001 | 1076 (7.57) | 1022 (7.19) | 0.02 |
| Admission to ICU | 2800 (4.43) | 11 969 (35.6) | < 0.001 | 2470 (17.4) | 2746 (19.3) | 0.05 |
| Mechanical ventilation | 1430 (2.26) | 5666 (16.9) | < 0.001 | 1209 (8.50) | 1387 (9.76) | 0.04 |
Note: AMI = acute myocardial infarction, CAD = coronary artery disease, CCI = Charlson Comorbidity Index, CHF = congestive heart failure, COPD = chronic obstructive pulmonary disease, ICU = intensive care unit, SD = standard deviation.
↵* Propensity scores were calculated based on sex, age, index year and underlying comorbidities.
↵† Unless otherwise specified.
↵‡ All p values are based on the χ2 test except for mean age, which is based on the t test.
↵§ A standardized mean difference of ≤ 0.10 indicates a negligible difference between the 2 cohorts.