Table 5.
—[Section 2.1.1] Summary of Findings: LMWH for Extended Prophylaxis vs Placebo After Major Orthopedic Surgery (Up to 35 Days)52,53
| Outcomes | No. of Participants (Studies) | Quality of the Evidence (GRADE) | Relative Effect (95% CI) | Anticipated Absolute
Effects |
|
| Risk With Placebo | Risk Difference With LMWH for Extended Prophylaxis (95% CI) | ||||
| Nonfatal PE |
2,423 (6
studies) |
High |
RR 0.24 (0.04-1.4) |
Study population |
|
| 5 per 1,000 | |||||
| Contemporary population
(extended prophylaxis)a | |||||
| 5 per 1,000 |
4 fewer per 1,000 (from 5 fewer to 2 more) |
||||
| Symptomatic DVT |
2,647 (7
studies) |
High |
RR 0.46 (0.26-0.82)b |
Study population |
|
| 33 per 1,000 | |||||
| Contemporary population
(extended prophylaxis)a | |||||
| 10 per 1,000 |
5 fewer per 1,000 (from 2 fewer to 7 fewer) |
||||
| Bleeding requiring reoperation |
0 (0) |
|
|
|
|
| Major nonfatal bleeding |
2,725 (7 studiesc) |
Highd |
RR 0.43 (0.11-1.65) |
5 per 1,000e |
3 fewer per 1,000 (from 4 fewer to 3 more) |
| Total mortalityf | 2,725 (7 studiesc) | Highd | RR 0.39 (0.08-1.98) | 2 per 1,000 | 1 fewer per 1,000 (from 2 fewer to 2 more) |
Contemporary surgical population from which baseline risk of patient-important outcomes has been derived (contemporary era surgical technique, early mobilization, etc [see text for details on how baseline risks were calculated]).
Number of events taken directly from Hull et al52 but relative risk recalculated using random-effects model.
This outcome was not presented in a forest plot in the original meta-analysis. Data were reextracted from the original publication for this outcome and pooled using a fixed-effects model (same method as presented in the original publication).
Not downgraded for imprecision because CI around absolute events is narrow.
All events were drop in hemoglobin level of ≥ 2 g/dL.
Deaths placebo: two from VTE and one from other causes. Deaths LMWH: death from other causes (pneumonia).