Table 2 Patients’ baseline characteristics for the derivation, geographic and temporal external validation sub-cohorts
Cohort | Derivation (UK until Jan 2011) | Geographic validation (non-UK) | Temporal validation (UK post-Jan 2011) | |||
|---|---|---|---|---|---|---|
Total number of patients | 462 | 515 | 323 | |||
Characteristics | Median or n | IQR or % | Median or n | IQR or % | Median or n | IQR or % |
|---|---|---|---|---|---|---|
Age | ||||||
Available data | 462 | 100% | 515 | 100% | 323 | 100% |
 18–34 | 11 | 2.4% | 25 | 4.9% | 11 | 3.4% |
 35–44 | 15 | 3.3% | 18 | 3.5% | 16 | 5% |
 45–54 | 54 | 11.7% | 52 | 10.1% | 38 | 11.8% |
 55–64 | 93 | 20.1% | 98 | 19% | 73 | 22.6% |
 65–74 | 113 | 24.5% | 151 | 29.3% | 88 | 27.2% |
 75–84 | 149 | 32.3% | 149 | 28.9% | 75 | 23.2% |
 85–95 | 27 | 5.8% | 22 | 4.3% | 22 | 6.8% |
Gender | ||||||
Available data | 462 | 100% | 515 | 100% | 323 | 100% |
 Male | 236 | 51.1% | 304 | 59% | 171 | 52.9% |
 Female | 226 | 48.9% | 211 | 41% | 152 | 47.1% |
Race | ||||||
Available data | 460 | 99.6% | 510 | 99% | 323 | 100% |
 Caucasian | 454 | 98.7% | 502 | 98.4% | 315 | 97.5% |
 Asian | 4 | 0.9% | 7 | 1.4% | 3 | 0.9% |
 African | 1 | 0.2% | 1 | 0.2% | 3 | 0.9% |
 Mixed | 1 | 0.2% | 0 | 0% | 2 | 0.6% |
Medical comorbidities | ||||||
Available data | 462 | 100% | 515 | 100% | 323 | 100% |
 Heart and vascular disease | 187 | 40.6% | 202 | 39.2% | 117 | 36.2% |
 Respiratory disease | 111 | 24.1% | 133 | 25.8% | 97 | 30% |
 Neurological disease | 48 | 10.4% | 57 | 11.1% | 24 | 7.4% |
 Severe renal disease | 39 | 8.6% | 21 | 4.3% | 16 | 5% |
 Gastrointestinal disease | 98 | 21.3% | 132 | 25.7% | 76 | 23.5% |
 Malignancy | 135 | 29.3% | 160 | 31.1% | 84 | 26% |
 Diabetes | 61 | 13.2% | 102 | 19.8% | 44 | 13.6% |
 Previous serious infectiona | 8 | 1.7% | 25 | 4.9% | 5 | 1.6% |
 Other illness | 130 | 28.2% | 210 | 40.8% | 83 | 25.7% |
 Severe exercise restriction | 3 | 0.7% | 6 | 1.2% | 1 | 0.3% |
 Chronic dialysis | 5 | 1.1% | 8 | 1.6% | 5 | 1.6% |
 Chronic steroids useb | 2 | 0.4% | 9 | 1.8% | 5 | 1.6% |
Cause of FP | ||||||
Available data | 461 | 99.8% | 511 | 99.2% | 323 | 100% |
 Perforated diverticulum | 137 | 29.7% | 175 | 34.3% | 89 | 27.6% |
 Anastomotic breakdown | 115 | 25% | 187 | 36.6% | 61 | 18.9% |
 Malignancy | 65 | 14.1% | 64 | 12.5% | 35 | 10.8% |
 Trauma | 22 | 4.8% | 45 | 8.8% | 16 | 5% |
 Other | 122 | 26.5% | 40 | 7.8% | 124 | 38.4% |
Time to surgery (days) | 1 | 1–3 | 1 | 1–3 | 1 | 1–3 |
Acute physiology | ||||||
Available data | 461 | 99.8% | 513 | 99.6% | 321 | 99.4% |
 APACHE II score | 15 | 12–20 | 17 | 13–22 | 16 | 12–21 |
 SOFA score | 7 | 5–9 | 7 | 5–11 | 6 | 5–8 |
 Acute renal failure | 129 | 32.7% | 214 | 42.8% | 70 | 21.8% |
 Renal replacement therapy | 81 | 21% | 105 | 21.3% | 26 | 8.1% |
 Mechanical ventilation | 346 | 75.1% | 397 | 77.4% | 228 | 71% |