Table 4.
The evidence profile (the quality of evidence evaluation and the summary of findings for each of the studied outcomes).
| Pain at Rest, 24 h | Morphine Requirements, 24 h (mg) | Postoperative Nausea and Vomiting | Pruritus | Hospital Stay Duration (Days) | |
| Risk of Bias | Very Serious | Very Serious | Very Serious | Serious | Very Serious |
| Lack of allocation concealment | Some concerns | Some concerns | Some concerns | No | Some concerns |
| Lack of blinding | Some concerns | Some concerns | Some concerns | No | Some concerns |
| Incomplete accounting of patients and outcome events | Some concerns | Some concerns | Some concerns | Some concerns | Some concerns |
| Selective outcome reporting | No | No | No | No | No |
| Other limitations | No | No | No | No | No |
| Inconsistency | Very serious | Very serious | Serious | Not serious | Serious |
| I2 (unexplained heterogeneity of results) | Considerable | Considerable | Moderate | None | Considerable |
| Wide variance of point estimates | No | Yes | Yes | No | Yes |
| Confidence intervals (CIs) do not overlap | Yes | Yes | No | No | No |
| Indirectness | Not serious | Not serious | Not serious | Serious | Not serious |
| Differences in population | No | No | No | No | No |
| Differences in interventions | No | No | No | No | No |
| Differences in outcome measures | No | No | No | Yes | No |
| Indirect comparisons | No | No | No | No | No |
| Imprecision | Not serious | Serious | Not serious | Not serious | Not serious |
| Few patients | Not serious | Not serious | Not serious | Not serious | Not serious |
| Wide confidence interval (CI) | Not serious | Serious | Not serious | Not serious | Not serious |
| Upgrading | None | None | None | RR < 0.5 | None |
| RR > 2 or RR < 0.5 RR > 5 or RR < 0.2 |
No | No | No | RR < 0.5 | No |
| Dose-response gradient | No | No | No | No | No |
| Effect of plausible residual confounding | No | No | No | No | No |