Summary of findings 2. Proportion of participants experiencing at least 50% of maximum pain relief at 6 hours.
| IV paracetamol/propacetamol compared to placebo or other analgesics for postoperative pain | |||||
| Patient or population: patients with postoperative pain Settings: hospital Intervention: IV paracetamol/propacetamol Comparison: placebo or other analgesics | |||||
| Comparison | Illustrative comparative risks* (95% CI) | Relative effect (95% CI) | No of participants (studies) | Quality of the evidence (GRADE) | |
| Assumed risk | Corresponding risk | ||||
| Placebo or other analgesics | IV paracetamol/propacetamol | ||||
| Para/propacetamol vs placebo see footnote1 | 97 per 1000 | 276 per 1000 (203 to 378) | RR 2.86 (2.1 to 3.91) | 1143 (10 studies) | ⊕⊕⊕⊝ moderate2,3,4 |
| Paracetamol vs placebo see footnote1 | 83 per 1000 | 304 per 1000 (179 to 517) | RR 3.65 (2.15 to 6.21) | 532 (6 studies) | ⊕⊕⊕⊝ moderate2,3,4 |
| Propacetamol vs placebo see footnote1 | 105 per 1000 | 252 per 1000 (172 to 367) | RR 2.4 (1.64 to 3.5) | 611 (6 studies) | ⊕⊕⊝⊝ low2,3,4,5,6 |
| Para/propacetamol vs NSAIDs see footnote1 | 632 per 1000 | 499 per 1000 (417 to 600) | RR 0.79 (0.66 to 0.95) | 355 (5 studies) | ⊕⊝⊝⊝ very low3,7,8 |
| Paracetamol vs NSAIDs see footnote1 | 623 per 1000 | 511 per 1000 (411 to 635) | RR 0.82 (0.66 to 1.02) | 212 (3 studies) | ⊕⊝⊝⊝ very low3,7,9,10 |
| Propacetamol vs NSAIDs see footnote1 | 649 per 1000 | 487 per 1000 (364 to 662) | RR 0.75 (0.56 to 1.02) | 143 (2 studies) | ⊕⊝⊝⊝ very low3,7,9,10 |
| Paracetamol vs propacetamol see footnote1 | 411 per 1000 | 386 per 1000 (300 to 493) | RR 0.94 (0.73 to 1.2) | 361 (3 studies) | ⊕⊕⊝⊝ low3,10 |
| *The basis for the assumed risk (e.g. the median control group risk across studies) is provided in footnotes. The corresponding risk (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; NNT = number needed to treat to benefit; NSAIDs: nonsteroidal anti‐inflammatory drugs; RR: risk ratio; SPID = summed pain intensity difference; TOTPAR = total pain relief; VAS: visual analog scale | |||||
| GRADE Working Group grades of evidence High quality: Further research is very unlikely to change our confidence in the estimate of effect. Moderate quality: Further research is likely to have an important impact on our confidence in the estimate of effect and may change the estimate. Low quality: Further research is very likely to have an important impact on our confidence in the estimate of effect and is likely to change the estimate. Very low quality: We are very uncertain about the estimate. | |||||
1TOTPAR or SPID using either VAS or categorical data, and calculating their corresponding percentage of theoretical maximum TOTPAR and SPID. 2Considerable unexplained heterogeneity exists between studies. 3Total # events <300. 4Large effect. 5One study data "not estimable" because of zero events in both groups. 6Publication bias favoring propacetamol; < 400 additional participants needed in studies with zero effect (relative benefit of one) required to change the NNT for at least 50% maximum pain relief to an unacceptably high level (in this case a NNT of 10). 7Different NSAIDs studied. 8Publication bias for superiority of NSAID; < 400 additional participants needed in studies with zero effect (relative benefit of one) required to change the NNT for at least 50% maximum pain relief to an unacceptably high level (in this case a NNT of 10). 9All individual studies < 100 participants. 10Wide confidence interval that includes no effect and appreciable benefit and/or harm.