New evidence contradicts previous studies
Two prior studies showed that using 30 to 40 mm Hg ECS decreased the incidence of PTS after proximal DVT.6,7 However, these were smaller, open-label, single-center studies. This study by Kahn et al1 was the first placebo-controlled, randomized, multicenter study that used validated instruments to measure PTS and QOL. It found no benefit in using ECS, thus contradicting the results of the prior studies.
There are currently no guidelines or consensus statements that recommend for or against the use of ECS after DVT.
High nonadherence rates might have affected results
In both groups, adherence to the assigned intervention diminished throughout the study (from 95% at one month to slightly less than 70% at two years). Theoretically, this could have affected efficacy outcomes. However, the decrease was similar in both groups and represents what is observed in clinical practice. A prespecified per protocol analysis of patients who wore their ECS more regularly found no benefit.
It is possible that a “placebo effect” could explain the lack of difference between groups. However, the placebo stockings provided virtually no compression, and the two-year cumulative incidence of PTS in both the treatment and placebo groups was similar to that seen in control groups in prior studies.6,7
Finally, the incidence of PTS in this study was much lower than the 25% to 50% incidence reported previously. Kahn et al1 suggested that this was because they used more stringent and standardized criteria for PTS than was used in previous research.
CHALLENGES TO IMPLEMENTATION
There are no barriers to ending this practice
We can identify no challenges to implementation of this recommendation.
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