Summary of findings 1. Summary of findings table ‐ Combined mechanical and oral antibiotic bowel preparation versus mechanical bowel preparation alone.
| Combined mechanical and oral antibiotic bowel preparation versus mechanical bowel preparation alone | ||||||
| Patient or population: Patients undergoing elective colorectal surgery Setting: Any type of hospital offering elective colorectal resections. Both single and multicentre studies are included Intervention: MBP+oAB Comparison: MBP | ||||||
| Outcomes | Anticipated absolute effects* (95% CI) | Relative effect (95% CI) | № of participants (studies) | Certainty of the evidence (GRADE) | Comments | |
| Risk with MBP | Risk with MBP+oAB | |||||
| SSI follow‐up: 30 days | 137 per 1000 | 77 per 1000 (58 to 101) | RR 0.56 (0.42 to 0.74) | 3917 (16 RCTs) | ⊕⊕⊕⊝ Moderatea | Combined mechanical and oral antibiotic bowel preparation probably results in a reduction in surgical site infections. |
| Anastomotic leakage follow‐up: 30 days | 44 per 1000 | 26 per 1000 (16 to 43) | RR 0.60 (0.36 to 0.99) | 2356 (10 RCTs) | ⊕⊕⊕⊝ Moderateb | Combined mechanical and oral antibiotic bowel preparation may result in a reduction in anastomotic leakage. |
| Mortality follow‐up: 30 days | 18 per 1000 | 16 per 1000 (5 to 51) | RR 0.87 (0.27 to 2.82) | 639 (3 RCTs) | ⊕⊕⊕⊝ Moderatec | Combined mechanical and oral antibiotic bowel preparation may result in no difference in mortality. |
| Incidence of postoperative ileus follow‐up: 30 days | 49 per 1000 | 43 per 1000 (29 to 64) | RR 0.89 (0.59 to 1.32) | 2013 (6 RCTs) | ⊕⊕⊝⊝ Lowd,e | Combined mechanical and oral antibiotic bowel preparation may result in no difference in incidence of postoperative ileus. |
| Length of hospital stay follow‐up: 30 days | MD 0.19 lower (1.81 lower to 1.44 higher) | ‐ | 621 (3 RCTs) | ⊕⊕⊕⊝ Moderated | Combined mechanical and oral antibiotic bowel preparation may result in no difference in length of hospital stay. | |
| *The risk in the intervention group (and its 95% confidence interval) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI). CI: confidence interval; MD: mean difference; RR: risk ratio | ||||||
| GRADE Working Group grades of evidence High certainty: we are very confident that the true effect lies close to that of the estimate of the effect. Moderate certainty: we are moderately confident in the effect estimate: the true effect is likely to be close to the estimate of the effect, but there is a possibility that it is substantially different. Low certainty: our confidence in the effect estimate is limited: the true effect may be substantially different from the estimate of the effect. Very low certainty: we have very little confidence in the effect estimate: the true effect is likely to be substantially different from the estimate of effect. | ||||||
| See interactive version of this table: https://gdt.gradepro.org/presentations/#/isof/isof_question_revman_web_431253836665717559. | ||||||
a The rating was downgraded by one level due to moderate heterogeneity between studies that could not be explained by the subgroup analyses; I2 =44%. b The rating was downgraded by one level for imprecision. Few events occurred in the included trials (28 in the intervention group and 52 in the control group) and the confidence intervals include both benefits and no effect. c The rating was downgraded by one level for imprecision. Few events occurred in the included studies (5 in the intervention group and 6 in the control group) and the confidence intervals include considerable benefit and harm. d The rating was downgraded by one level due to imprecision, as the confidence interval includes considerable benefit and harm. e The rating was downgraded by one level due to possible puplication bias, as small studies reported statistically significant benefits while larger studies showed a much smaller and statistically non‐significant effect.