executive summary- an argument can be made that 1 in 50 flyers might get a DVT, especially if they aren't seated in an aisle. compression socks alone reduced this incidence in the treatment group to 0, apparently.

I wear Jobst and I don't have a financial interest in the company


1. Angiology. 2002 Nov-Dec;53(6):635-45.

Prevention of edema, flight microangiopathy and venous thrombosis in long flights
with elastic stockings. A randomized trial: The LONFLIT 4 Concorde Edema-SSL
Study.

Belcaro G, Cesarone MR, Shah SS, Nicolaides AN, Geroulakos G, Ippolito E, Winford
M, Lennox A, Pellegrini L, Brandolini R, Myers KA, Simeone E, Bavera P, Dugall M,
Di Renzo A, Moia M.

Department of Biomedical Sciences, Irvine2 Vascular Laboratory, G. D'Annunzio
University, and San Valentino Vascular Screening Project (Pe), Italy.
[email protected]

The LONFLIT1/2 studies have established that in high-risk subjects after long (>
10 hours) flights the incidence of deep venous thrombosis (DVT) is between 4% and
6%. The LONFLIT4 study has been planned to evaluate the control of edema and DVT
in low-medium-risk subjects. The aim of this study was to evaluate edema and its
control with specific flight stockings, in long-haul flights. In the first part
of the study 400 subjects at low-medium risk for DVT were contacted; 28 were
excluded for several nonmedical problems; 372 were randomized into 2 groups to
evaluate prophylaxis with stockings in 7-8-hour flights; the control group had no
prophylaxis. Below-knee, Scholl, Flight Socks, producing 14-17 mm Hg of pressure
at the ankle, were used in the treatment group. The occurrence of DVT was
evaluated with high-resolution ultrasound scanning (femoral, popliteal, and
tibial veins). Edema was assessed with a composite score based on parametric and
nonparametric measurements. Part II: In this part of the study 285 subjects at
low-medium risk for DVT were included and randomized into 2 groups to evaluate
edema prophylaxis in 11-12-hour flights; the controls had no prophylaxis while
the prevention group had below-knee, Scholl, Flight Socks (comparable to part I).
RESULTS: Part 1: DVT evaluation. Of the 184 included subjects in the stockings
group and 188 in the control group, 358 (96.2%) completed the study. Dropouts
were due to compliance or connection problems. Age/sex distributions were
comparable in the groups. Stockings Group: of 179 subjects (mean age 49; SD 7;
M:F = 101:78), none had DVT or superficial thromboses. Control Group: of 179
subjects (mean age 48.4; SD 7.3; M:F = 98:81), 4 (2.2%) had a DVT. There were
also 2 superficial thromboses. In total, 3.35% (6) subjects had a thrombotic
event. The difference (p<0.002) is significant. Intention-to-treat analysis
detects 15 failures in the control group (9 lost + 6 thromboses) out of 188
subjects (7.9%) versus 5 subjects (2.7%) in the stockings group (p <0.05). All
thrombotic events were observed in passengers sitting in nonaisle seats. The
tolerability of the stockings was very good and there were no complaints or side
effects. Thrombotic events were asymptomatic. No difference was observed in the
distribution of events between men and women. The 3 women who had a thrombotic
event were taking low-dose, oral contraceptives. Edema evaluation: The level of
edema at inclusion was comparable in the 2 groups. After the flight there was a
score of 6.7 (3.1) in controls; in the stockings group the score was 2.9 times
lower (p<0.05). The control of edema with stockings was clear considering both
parametric (circumference, volume) and nonparametric (analogue scale lines) data.
Part II: DVT evaluation. Of the 285 included subjects, 271 (95%) completed the
study. Dropouts were due to low compliance or connection problems. Age/sex
distributions were comparable in the groups. Stockings Group: of 142 subjects
(mean age 48; SD 8; M:F = 89:53), none had DVT or superficial thromboses. Control
Group: of 143 subjects (mean age 47; SD 8; M:F = 87:56), 3 had a popliteal DVT
and 3 a superficial thrombosis. In total, 4.2% (6) subjects had a thrombotic
event. The difference (p<0.02) between groups is significant. Intention-to-treat
analysis detects 14 failures in the control group (8 lost + 6 thromboses = 9.7%)
versus 6 (all lost = 4.2% in the stockings group) (p<0.05). Four of 6 events (3
DVT + 1 SVT) were observed in non-aisle seats. The tolerability of the stockings
was very good. No difference was observed in the distribution of events between
men and women. Edema evaluation: The level of edema at inclusion was comparable
in the 2 groups. After the flight there was a score of 8.08 (2.9) in controls
while in the stockings group the score was 2.56 (1.5) (p < 0.005). In conclusion.
Scholl Flight Socks are very effective in controlling edema. Also this type of
compression is effective in significantly reducing the incidence of DVT and
thrombotic events in low-medium-risk subjects, in long-haul flights. CONCLUSIONS:
Considering these observations, Flight Socks are effective in controlling edema
and in reducing the incidence of DVT in low-medium-risk subjects, in long-haul
flights (7-11 hours).