Table 14.

—[Section 2.13] Summary of Findings: Vena Cava Filter vs No Vena Cava Filter for Acute Proximal DVT of the Leg Treated With Anticoagulation^a,b,146,443

Outcomes	No. of Participants (Studies), Follow-up	Quality of the Evidence (GRADE)	Relative Effect (95% CI)	Anticipated Absolute Effects
				Risk With No vena cava Filters	Risk Difference With Vena cava Filters (95% CI)
Mortality	400 (1 study), 8 y	Moderatec,d due to imprecision	RR 0.95 (0.78-1.16)e	515 per 1,000	26 fewer per 1,000 (from 113 fewer to 82 more)
Symptomatic PE	304 (1 study), 8 y	Moderatec,f due to imprecision	RR 0.41 (0.2-0.86)g	151 per 1,000	89 fewer per 1,000 (from 21 fewer to 121 fewer)
Recurrent DVT	310 (1 study), 8 y	Moderatec,f due to imprecision	RR 1.3 (0.93-1.82)h	273 per 1,000	82 more per 1,000 (from 19 fewer to 224 more)
Major bleeding	337 (1 study), 8 y	Moderatec,d due to imprecision	RR 0.83 (0.52-1.34)i	185 per 1,000	31 fewer per 1,000 (from 89 fewer to 63 more)
PTS	308 (1 study), 8 y	Lowd,j due to risk of bias and imprecision	RR 0.87 (0.66-1.13)	699 per 1,000	91 fewer per 1,000 (from 238 fewer to 91 more)
Complications	379 (1 study), 2 y	Moderatef due to imprecision	…	…	k
QOL not reported	…	…	…	…	…

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. PREPIC = Prevention du Risque d’Embolie Pulmonaire par Interruption Cave. See Table 1 and 3 legends for expansion of other abbreviations.

^aAnticoagulation consisted of LMWH or UFH initially (according to a 2 × 2 factorial design) followed by oral anticoagulation for at least 3 mo.

^bFour types of permanent vena cava filters were used: Vena Tech LGM (B. Braun Melsugen AG), titanium Greenfield (Boston Scientific Corporation), Cardial (C.R. Bard, Inc), and Bird’s Nest (Cook Group Incorporated).

^cAllocation was concealed. Data collectors and outcome adjudicators were blinded. Intention-to-treat analysis. Data missing for 4% at 2 y and 1% at 8 y. Enrollment was stopped at 400 instead of targeted 800 because of slow recruitment.

^dCI includes both negligible effect and appreciable benefit or appreciable harm.

^eRR, 1.0 (95% CI, 0.29-3.4) at 12 d; RR, 1.08 (95% CI, 0.73-1.58) at 2 y.

^fSmall number of events.

^gRR. 0.23 (95% CI, 0.05-1.05) at 12 d (both symptomatic and asymptomatic PE). RR, 0.54 (0.21-1.41) at 2 y (symptomatic PE).

^hRR, 1.78 (95% CI, 1.09-2.94) at 2 y.

ⁱRR, 1.5 (95% CI, 0.54-4.14) at 12 d. RR, 0.74 (95% CI, 0.41-1.36) at 2 y.

^jNo standardized validated tool used to measure PTS.

^kNo complications directly related to the filter or its insertion reported in the PREPIC trial.¹⁴⁶ Mismetti et al¹⁴⁷ (prospective study) reported an incidence of 3.2% (excluding filter tilting and puncture site hematoma) among 220 patients receiving a retrievable vena cava filter for secondary prevention of VTE, whereas Athanasoulis et al¹⁴⁸ (retrospective study) reported an incidence of 0.3% for major complications among 1,731 patients receiving vena cava filters predominantly for secondary prevention of VTE.