Table 5.
Relative risk of postoperative infection based on adherence to six critical standards in infection prevention, after adjusting for sex, age, urgency, wound class and hospital using modified robust Poisson regression
| Relative risk | P | |
|---|---|---|
| Adherence score | ||
| 0–2 | 1·00 (reference) | |
| 3–6 | 0·54 (0·30, 0·97) | 0·038 |
| Sex | ||
| F | 1·00 (reference) | |
| M | 0·82 (0·51, 1·32) | 0·414 |
| Age (years) | ||
| ≤ 25 | 1·00 (reference) | |
| 26–30 | 0·72 (0·45, 1·14) | 0·162 |
| 31–40 | 0·82 (0·51, 1·32) | 0·418 |
| ≥ 41 | 0·80 (0·45, 1·44) | 0·460 |
| Urgency | ||
| Elective | 1·00 (reference) | |
| Emergency | 1·08 (0·68, 1·72) | 0·740 |
| Wound class | ||
| Clean | 1·00 (reference) | |
| Clean contaminated | 0·40 (0·09, 1·83) | 0·237 |
| Contaminated | 0·87 (0·19, 4·07) | 0·860 |
| Dirty | 2·10 (0·45, 9·77) | 0·345 |
| Type of operation | ||
| Ear, nose and throat | 1·00 (reference) | |
| Orthopaedic | 4·38 (0·60, 32·24) | 0·147 |
| Soft tissue | 3·47 (0·85, 14·14) | 0·083 |
| Gynaecological | 3·99 (0·59, 26·88) | 0·155 |
| Vascular | 1·14 (0·11, 11·33) | 0·912 |
| Appendicectomy | 4·76 (0·74, 30·69) | 0·101 |
| Cholecystectomy | 9·37 (1·10, 79·70) | 0·041 |
| Colorectal | 11·08 (1·74, 70·58) | 0·011 |
| Caesarean | 9·94 (1·58, 62·72) | 0·015 |
| Hernia | 2·33 (0·40, 13·46) | 0·343 |
| Hysterectomy | 11·08 (1·45, 84·72) | 0·021 |
| Gastrointestinal/laparotomy | 5·41 (0·92, 31·90) | 0·062 |
| Urological | 4·01 (0·31, 51·93) | 0·288 |
Values in parentheses are 95 per cent confidence intervals. The analysis was based on 2159 procedures. Relative risks by hospital are not shown.