Table 6.
—[Section 2.5.1] Summary of Findings: LMWH vs IV UFH for Initial Anticoagulation of Acute VTE74
| Outcomes | No. of Participants (Studies), Follow-up | Quality of the Evidence (GRADE) | Relative Effect (95% CI) | Anticipated Absolute
Effects |
|
| Risk With IV UFH | Risk Difference With LMWH (95% CI) | ||||
| All-cause mortality |
7,908 (17 studies), 3 mo |
Lowa,b due
to risk of bias, publication bias |
RR 0.79 (0.66-0.95) |
46 per 1,000c |
10 fewer per 1,000 (from 2 fewer to 16 fewer) |
| Recurrent VTE |
7,976 (17 studies), 3 mo |
Lowa,b due
to risk of bias, publication bias |
RR 0.72 (0.58-0.89) |
55 per 1,000c |
15 fewer per ,1000 (from 6 fewer to 23 fewer) |
| Major bleeding | 6,910 (20 studies), 3 mo | Lowa,b,d due to risk of bias, publication bias | RR 0.67 (0.45-1) | 15 per 1,000c | 5 fewer per 1,000 (from 8 fewer to 0 more) |
The basis for the assumed risk (eg, the median control group risk across studies) is provided in footnotes. The corresponding risk (and its 95% CI) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI). Working group grades of evidence are as follow: 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. See Table 1 and 3 legends for expansion of abbreviations.
Of the 20 trials, allocation was concealed in nine and was unclear whether concealed in the remaining 11. In 18 trials, outcome assessors were blinded. Seven trials did not have any postrandomization exclusions or losses to follow-up. Ten trials reported the number of participants lost to follow-up, which ranged from 1.0% to 12.7%. One trial did not report the drop-outs.
Inverted funnel plot very suggestive of publication bias. Many of the included studies are of small size, and all were funded by industry.
Event rate corresponds to the median event rate in the included studies.
CI includes values suggesting significant benefit and no effect.