Cochrane Database Syst Rev. 2016 Sep 14
Compression stockings for preventing deep vein thrombosis
in airline passengers.
Clarke MJ1, Broderick C, Hopewell S, Juszczak E,
1Centre for Public Health, Queen's University
Belfast, Institute of Clinical Sciences, Block B, Royal Victoria Hospital,
Grosvenor Road, Belfast, Northern Ireland, UK, BT12 6BJ.
Air travel might increase the risk of deep vein thrombosis
(DVT). It has been suggested that wearing compression stockings might reduce
this risk. This is an update of the review first published in 2006.
To assess the effects of wearing compression stockings
versus not wearing them for preventing DVT in people travelling on flights
lasting at least four hours.
For this update the Cochrane Vascular Information Specialist
(CIS) searched the Specialised Register (10 February 2016). In addition, the
CIS searched the Cochrane Register of Studies (CENTRAL (2016, Issue 1)).
Randomised trials of compression stockings versus no
stockings in passengers on flights lasting at least four hours. Trials in which
passengers wore a stocking on one leg but not the other, or those comparing
stockings and another intervention were also eligible.
DATA COLLECTION AND ANALYSIS:
Two review authors independently selected trials for
inclusion and extracted data. We sought additional information from trialists
One new study that fulfilled the inclusion criteria was
identified for this update. Eleven randomised trials (n = 2906) were included
in this review: nine (n = 2821) compared wearing graduated compression
stockings on both legs versus not wearing them; one trial (n = 50) compared
wearing graduated compression tights versus not wearing them; and one trial (n
= 35) compared wearing a graduated compression stocking on one leg for the
outbound flight and on the other leg on the return flight. Eight trials
included people judged to be at low or medium risk of developing DVT (n = 1598)
and two included high-risk participants (n = 1273). All flights had a duration
of more than five hours.Fifty of 2637 participants with follow-up data
available in the trials of wearing compression stockings on both legs had a
symptomless DVT; three wore stockings, 47 did not (odds ratio (OR) 0.10, 95%
confidence interval (CI) 0.04 to 0.25, P < 0.001; high-quality evidence). There
were no symptomless DVTs in three trials. Sixteen of 1804 people developed
superficial vein thrombosis, four wore stockings, 12 did not (OR 0.45, 95% CI
0.18 to 1.13, P = 0.09; moderate-quality evidence). No deaths, pulmonary emboli
or symptomatic DVTs were reported. Wearing stockings had a significant impact
in reducing oedema (mean difference (MD) -4.72, 95% CI -4.91 to -4.52; based on
six trials; low-quality evidence). A further two trials showed reduced oedema
in the stockings group but could not be included in the meta-analysis as they
used different methods to measure oedema. No significant adverse effects were
There is high-quality
evidence that airline passengers similar to those in this review can expect a
substantial reduction in the incidence of symptomless DVT and low-quality
evidence that leg oedema is reduced if they wear compression stockings. Quality
was limited by the way that oedema was measured. There is moderate-quality
evidence that superficial vein thrombosis may be reduced if passengers wear
compression stockings. We cannot assess the effect of wearing stockings on
death, pulmonary embolism or symptomatic DVT because no such events occurred in
these trials. Randomised trials to assess these outcomes would need to include
a very large number of people.