Table 1.
Demographics and baseline characteristics
| Intervention (n = 681) |
Control (n = 663) |
P* | |
|---|---|---|---|
| Age (years) | 0.083 | ||
| ȃMean(s.d.) | 67.6(16.8) | 66.0(17.5) | |
| ȃMedian (range) | 71 (18–97) | 69 (18–96) | |
| Sex ratio (M : F) | 317 : 364 | 302 : 361 | 0.75 |
| BMI (kg/m2) | n = 429 | n = 594 | 0.07 |
| ȃMean(s.d.) | 26.2(5.5) | 25.6(5.6) | |
| ȃMedian (range) | 25.4 (12.8–47.8) | 24.7 (11.1–67.5) | |
| Co-morbidity | |||
| ȃChronic obstructive lung disease | 67 (9.8) | 54 (8.1) | 0.32 |
| ȃIschaemic heart disease | 95 (14.0) | 80 (12.1) | 0.34 |
| ȃCongestive heart failure | 44 (6.5) | 59 (8.9) | 0.11 |
| ȃDiabetes | 84 (12.3) | 76 (11.5) | 0.68 |
| ȃChronic renal failure | 26 (3.8) | 30 (4.5) | 0.61 |
| ȃObesity | 99 (14.5) | 82 (12.4) | 0.28 |
| ȃSmoking | 80 (11.7) | 86 (13.0) | 0.55 |
| ȃNo co-morbidity | 357 (52.4) | 333 (50.2) | 0.45 |
| ASA physical status grade | 0.44 | ||
| ȃI | 48 (7.0) | 72 (10.9) | |
| ȃII | 254 (37.3) | 222 (33.5) | |
| ȃIII | 280 (41.1) | 264 (39.8) | |
| ȃIV | 79 (11.6) | 94 (14.2) | |
| ȃV | 20 (2.9) | 11 (1.7) | |
| Diagnosis at surgery | |||
| ȃPeritonitis | 0.015 | ||
| ȃȃNo peritonitis | 532 (78.1) | 489 (73.8) | |
| ȃȃPurulent | 38 (5.6) | 42 (6.3) | |
| ȃȃFaecal | 59 (8.7) | 48 (7.2) | |
| ȃȃOther | 52 (7.6) | 84 (12.7) | |
| ȃIntestinal ischaemia | 91 (13.4) | 76 (11.5) | 0.33 |
| ȃBowel obstruction | 0.049 | ||
| ȃȃNo obstruction | 273 (40.3) | 277 (42.0) | |
| ȃȃSmall intestine | 304 (44.9) | 314 (47.6) | |
| ȃȃColon | 100 (14.8) | 68 (10.3) | |
| ȃȃMissing | 4 | 4 | |
| ȃTrauma | 15 (2.2) | 20/661 (3.0) | 0.44 |
| ȃBleeding | 33 (4.8) | 41/659 (6.2) | 0.33 |
| ȃPerforation | 0.027 | ||
| ȃȃNo perforation | 469 (69.5) | 460 (69.4) | |
| ȃȃColon | 87 (12.9) | 57 (8.6) | |
| ȃȃSmall intestine | 62 (9.2) | 72 (10.9) | |
| ȃȃVentricle | 37 (5.5) | 56 (8.4) | |
| ȃȃAnastomosis | 20 (3.0) | 18 (2.7) | |
| ȃȃMissing | 6 | 0 |
Values are n (%) unless otherwise indicated. *Between-groups Fisher’s exact test (lowest 1-sided P-value multiplied by 2) for dichotomous variables, Mantel–Haenszel χ2 test for ordered categorical variables, χ2 test for non-ordered categorical variables, and Fisher’s non-parametric permutation test for continuous variables.