Table 3. Summarized outcomes in Grading of Recommendations Assessment, Development and Evaluation (GRADE) for each major intervention.
| Table 3 summary of findings: | |||||
|---|---|---|---|---|---|
| Continuous femoral nerve block compared to Placebo or no intervention for pain after TKA | |||||
| Patient or population: pain after TKA. Setting: The immediate postoperative setting. Intervention: Continuous femoral nerve block. Comparison: Placebo or no intervention | |||||
| Outcomes | Anticipated absolute effects* (95% CI) | Relative effect (95% CI) | No of participants (studies) | Quality of the evidence (GRADE) | |
| Risk with Placebo or no intervention | Risk with Continuous femoral nerve block | ||||
| Morphine consumption assessed with: 0–24 hour postoperative | The mean morphine consumption was 20.5 mg | The mean morphine consumption in the intervention group was 12.3 mg lower (9.7 lower to 14.8 lower) | - | 264 (6 RCTs) | ⨁⨁⨁◯ MODERATE a |
| Pain score 6 h postoperative at rest assessed with: VAS 0–100 | The mean pain score 6 h postoperative at rest was 20 mm | The mean pain score 6 h postoperative at rest in the intervention group was 10 mm lower (2 lower to 19 lower) | - | 308 (6 RCTs) | ⨁◯◯◯ VERY LOW a,b,c,d |
| Pain score 24 h postoperative at rest assessed with: VAS 0–100 | The mean pain score 24 h postoperative at rest was 33 mm | The mean pain score 24 h postoperative at rest in the intervention group was 16 mm lower (8 lower to 23 lower) | - | 404 (8 RCTs) | ⨁⨁◯◯ LOW a,b,e |
| Pain score 24 h postoperative at movement assessed with: VAS 0–100 | The mean pain score 24 h postoperative at movement was 64 mm | The mean pain score 24 h postoperative at movement in the intervention group was 10 mm lower (4 lower to 15 lower) | - | 183 (4 RCTs) | ⨁⨁⨁◯ MODERATE a |
| Postoperative nausea and vomiting (PONV) assessed with: Number of events | 580 per 1,000 | 429 per 1,000 (313 to 597) | RR 0.74 (0.54 to 1.03) | 220 (5 RCTs) | ⨁⨁◯◯ LOW a,c,f |
| Sedation assessed with: Number of events | 286 per 1,000 | 380 per 1,000 (37 to 1,000) | RR 1.33 (0.13 to 13.66) | 167 (3 RCTs) | ⨁◯◯◯ VERY LOW a,b,c,f |
| Pruritus assessed with: Number of events | 507 per 1,000 | 573 per 1,000 (457 to 716) | RR 1.13 (0.90 to 1.41) | 175 (3 RCTs) | ⨁⨁◯◯ LOW a,c,f |
| Length of stay (LOS) | The mean length of stay was 6.4 days | The mean length of stay in the intervention group was 0.3 days lower (0.8 lower to 0.2 higher) | - | 171 (3 RCTs) | ⨁⨁◯◯ LOW a,c,f |
| *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 quality: We are very confident that the true effect lies close to that of the estimate of the effect. Moderate quality: 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 quality: Our confidence in the effect estimate is limited: The true effect may be substantially different from the estimate of the effect. Very low quality: We have very little confidence in the effect estimate: The true effect is likely to be substantially different from the estimate of effect. | |||||
a. There were studies of unclear and high summarized risk of bias.
b. There was heterogeneity as noted by I^2.
c. There were less than 400 participants in total.
d. The intervention did not reach either threshold for significance or a priori estimated information size in trial sequential analysis.
e. Low assay sensitivity in Seet et al explains the heterogeneity.
f. 95% confidence interval includes 'no effect'.