Table 1.
Baseline patient demographic and hospital characteristics according to presence or absence of post-operative sepsisa (n = 144,503)
| Characteristics | Non-sepsis | Sepsis | IR of sepsis |
|---|---|---|---|
| Total | 142,646 | 1857 | 12.9 |
| Year of admission | |||
| 2007 | 23,564 (16.5%) | 281 (15.1%) | 11.8 |
| 2008 | 23,993 (16.8%) | 293 (15.8%) | 12.1 |
| 2009 | 23,305 (16.3%) | 280 (15.1%) | 11.9 |
| 2010 | 24,447 (17.1%) | 324 (17.5%) | 13.1 |
| 2011 | 24,195 (17.0%) | 315 (17.0%) | 12.9 |
| 2012 | 23,142 (16.2%) | 364 (19.6%) | 15.5 |
| Hospitalisation in preceding year | |||
| 2007 | N/A | N/A | |
| 2008 | 2275/23,993 (9.5%) | 35/293 (12.0%) | |
| 2009 | 2734/23,305 (11.7%) | 40/280 (14.3%) | |
| 2010 | 3344/24,447 (13.7%) | 46/324 (14.2%) | |
| 2011 | 3771/24,195 (15.6%) | 54/315 (17.1%) | |
| 2012 | 3889/23,142 (16.8%) | 64/364 (17.6%) | |
| Age | |||
| ≥18 years to <35 years | 8838 (6.2%) | 106 (5.7%) | 11.9 |
| ≥35 years to <55 years | 28,015 (19.6%) | 348 (18.7%) | 12.3 |
| ≥55 years to <75 years | 64,382 (45.1%) | 814 (43.8%) | 12.5 |
| ≥75 years | 41,411 (29.0%) | 589 (31.7%)* | 14 |
| Mean ± SD | 63.8 ± 16.3 | 64.8 ± 16.3** | |
| Sex | |||
| Male | 67,011 (47.0%) | 1147 (61.8%)** | 16.8 |
| Female | 75,635 (53.0%) | 710 (38.2%)** | 9.3 |
| Country of birth | |||
| Australia and New Zealand | 98,787 (69.3%) | 1249 (67.3%) | 12.5 |
| United Kingdom, United States and Canada | 10,205 (7.2%) | 111 (6.0%)* | 10.8 |
| Non-English-speaking Europe | 15,949 (11.2%) | 220 (11.8%) | 13.6 |
| North Africa | 5564 (3.9%) | 78 (4.2%) | 13.8 |
| Asia | 6,922 (4.9%) | 93 (5.0%) | 13.3 |
| Others | 4,222 (3.0%) | 77 (4.1%)** | 17.9 |
| Unknown | 997 (0.7%) | 29 (1.6%)** | 28.3 |
| Marital status | |||
| Married | 77,810 (54.6%) | 1005 (54.1%) | 12.8 |
| Single | 62,745 (44.0%) | 805 (43.3%) | 12.7 |
| Unknown | 1923 (1.3%) | 47 (2.5%)** | 23.9 |
| Severity of illness/co-morbidity | |||
| Normal | 116,031 (81.3%) | 969 (52.2%)** | 8.3 |
| Moderate | 16,509 (11.6%) | 322 (17.3%)** | 19.1 |
| Severe | 5700 (4.0%) | 213 (11.5%)** | 36.0 |
| Very severe | 4406 (3.1%) | 353 (19.0%)** | 74.2 |
| SEIFA scores | |||
| First quartile (most disadvantaged) | 48,634 (34.1%) | 590 (31.8%)* | 12 |
| Second quartile | 41,195 (28.9%) | 568 (30.6%) | 13.6 |
| Third quartile | 31,862 (22.3%) | 408 (22.0%) | 12.6 |
| Fourth quartile (most advantaged) | 19,888 (13.9%) | 267 (14.4%) | 13.2 |
| Unknown | 1067 (0.7%) | 24 (1.3%)** | 22 |
| Local health district of facilities | |||
| Metropolitan | 91,018 (63.8%) | 1336 (71.9%)** | 14.5 |
| Rural | 44,902 (31.5%) | 420 (22.6%)** | 9.3 |
| Unknown | 6726 (4.7%) | 101 (5.4%) | 14.8 |
| Peer hospital group | |||
| Principal referral | 85,108 (59.7%) | 1358 (73.1%)** | 15.7 |
| Ungrouped acute | 2418 (1.7%) | 6 (0.3%)** | 2.5 |
| Major metropolitan and non-metropolitan | 44,850 (31.4%) | 444 (23.9%)** | 9.8 |
| District groups 1 and 2 | 10,270 (7.2%) | 49 (2.6%)** | 4.7 |
| Major surgical procedure | |||
| CABG | 8994 (6.3%) | 186 (10.0%)** | 20.3 |
| Abdominal surgery | 33,506 (23.5%) | 649 (35.0%)** | 19.0 |
| EVAR | 1458 (1.0%) | 20 (1.1%) | 13.5 |
| Total hip replacement | 13,632 (9.6%) | 45 (2.4%)** | 3.3 |
| Total knee replacement | 22,598 (15.8%) | 57 (3.1%)** | 2.5 |
| Other | 62,458 (43.8%) | 900 (48.5%)** | 14.2 |
| Length of stay | |||
| Mean ± SD | 9.1 ± 9.6 | 33.4 ± 31.6 | |
| Median (IQR) | 6 (5–10) | 24 (14–42) | |
Abbreviations: IR Incidence rate of sepsis reported per 1000 admissions, SEIFA Socio-Economic Indexes for Areas, CABG Coronary artery bypass graft, EVAR Endovascular aneurysm repair
aThe two cohorts were compared by t test for continuous values or chi-square test for dichotomous values
*P ≤ 0.05 for difference between cohorts
**P ≤ 0.01 for difference between cohorts