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Veins and Lymphatics 2013; volume 2:e7

[Veins and Lymphatics 2013; 2:e7] [page 19]

Elastic or inelastic
compression?
Reported evidence
from clinical trials
Mieke Flour
University Hospital Leuven, Belgium

Abstract

Evidence for compression therapy found in
literature mainly comes from clinical studies,
preferably randomized controlled trials (RCTs)
and systematic reviews (SR), which are often
complemented by research data, expert opin-
ion or by data from technology assessment or
regularization documents. Differences
between materials/methods/intervention in
clinical trials can be partly explained by vari-
ability in focus, or due to country specific
issues. Results from RCTs and SRs, and the
interpretation of these results may vary
depending on definitions used and the adequa-
cy of data. In the first place, the baseline com-
parability of study groups depends very much
on the accuracy of the diagnosis. Secondly,
results will very much depend on the interven-
tion used, whether compression is used alone,
or whether it is part of a more complex man-
agement like decongestive treatment includ-
ing other physical methods, surgery, or phar-
macological treatment. A third consideration
relates to the outcome parameters, the meth-
ods used to measure them, and the length of
follow-up. Properties of compression materials
have been redefined and standardized, and
new insights in the physiological effects of
compression treatment have shaken existing
myths and dogmas in this field. RCTs using
out-dated definitions and classifications of
materials have led to systematic reviews and
recommendations based on the same misun-
derstanding; it is left to the alert reader to
interpret their results with caution.

Introduction

Grading and definition of the level of the
selected evidence vary between publications,
and this is usually described in the introduc-
tion of the manuscript. Either there will be
some objective ranking of the quality/reliabili-
ty of trials and evidence, or the recommenda-
tions combine objective ranking of the evi-
dence with other considerations for practice,
like the GRADE tool introduced by the
American College of Chest Physicians.4

There aren’t too many new relevant good
quality RCTs each year, so there will not be too
much difference between the source docu-
ments for systematic reviews, and thus most
recommendation documents on compression
therapy look very much alike indeed.

Variability in trials’ setup

Differences between materials/methods/
intervention in clinical trials can be partly
explained by variability in focus, or due to
country specific issues.

Focus may be differently accentuated e.g.
depending on authorship and target users
groups (nurses, versus medical specialties,
versus true multidisciplinary groups including
patients’ representatives). Also, the scope may
vary, depending on whether the intervention is
purely conservative (compression treatment,
education, etc.) versus that the consensus
includes additional recommendations on med-
ical/surgical interventions for etiological man-
agement and follow-up of the underlying dis-
ease (venous, lymphatic, thrombosis, etc.). Of
course, the scope will also depend on the spe-
cific selected indication or goal setting: the
trial or his outcomes may be aiming at getting
reimbursement from health care institutions
(like those from the Haute Autorité de santé in
France, the Dutch Institute for Healthcare
Improvement in the Netherlands), or aiming at
setting educational endpoints, or it is meant
for implementation of the uniform application
of materials and techniques throughout the
country (like in the Netherlands, or the 4-layer
bandaging in the UK). Country specific issues
may be the selection of bandages/stocking
types according to availability or local prefer-
ences (stockings preferred above bandages in
France? inelastic bandages preferred in the
older guidelines in some European countries).
National guidelines/recommendations on com-
pression treatment in specific indications
exist in countries like France, the Netherlands,
UK, Ireland, Italy, Germany, Canada, Australia,
New Zealand, Belgium, and many others.

National and International Societies have
issued consensus documents or best practice
documents regarding compression therapy,
and this will most probably influence the
choice of intervention by investigators.

Variability in trial outcomes
and recommendations

Results from RCTs and SRs, and the inter-
pretation of these results may vary depending
on definitions used and the adequacy of data.
In the first place, the baseline comparability of
study groups depends very much on the accu-
racy of the diagnosis. In still too many trials
and reviews the venous ulcer etiology is based
on a normal ankle brachial pressure index in a
patient with a leg ulcer clinically compatible
with a venous ulcer. Not only can the diagnosis
(based only on clinical examination) be erro-
neous, it can underestimate the severity and
extent of the problem and any relevant co-mor-
bidity. The accuracy of a venous etiological
diagnosis increases with the addition of imag-
ing and invasive testing in chronic venous dis-
orders. The American Venous Forum recom-
mends duplex scanning as the first diagnostic
test to all patients with suspected chronic
venous obstruction or valvular incompetence.

Secondly, results will very much depend on
the intervention used, be it compression alone
(on top of dressing choice), or complex decon-
gestive treatment including other physical
methods [physical therapy, intermittent pneu-
matic compression (IPC)], or a combination of
treatments including surgery, or pharmacolog-
ical treatment. In the Materials and Methods
paragraph of published trials and studies,
description of the type of compression treat-
ment should clearly state specific details, such
as: what is the definition and classification

Correspondence: Mieke Flour, Schoonzichtlaan
43, B-3020 Herent, Belgium. Tel. +32.478.566780.
E-mail: mie.flour@skynet.be

Key words: compression treatment, elastic,
inelastic, evidence, clinical trials.

Conference presentation: part of this paper was
presented at the International Compression Club
(ICC) Meeting on Stiffness of Compression
Devices, 2012 May 25, Vienna, Austria
(http://www.icc-compressionclub.com/).

Conflict of interests: the author reports no poten-
tial conflict of interests.

Received for publication: 14 November 2012.
Revision received: 2 January 2013.
Accepted for publication: 21 January 2013.

This work is licensed under a Creative Commons
Attribution 3.0 License (by-nc 3.0).

©Copyright M. Flour, 2013
Licensee PAGEPress, Italy
Veins and Lymphatics 2013; 2:e7
doi:10.4081/vl.2013.e7

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[page 20] [Veins and Lymphatics 2013; 2:e7]

used for compression materials (bandages,
stockings), is the applied pressure or stiffness
measured in vivo, is compression strength
described in (country specific) compression
classes or in mmHg, are the bandages and
stockings named and described so the reader
can agree or not with the label used for com-
pression materials (e.g. definitions like in the
BSI, or definitions like inelastic, elastic, short
stretch, long stretch, superposition of layers,
etc.). A third consideration relates to the out-
come parameters, the methods used to meas-
ure them, and the length of follow-up.

Interpretation of the results and the recom-
mendations issued from it, are very much
dependent on the above listed issues and
insights, which themselves have been the topic
of several recent consensus documents.5-7

Evidence for the effectiveness
of compression therapy

A comprehensive review of evidence regard-
ing effectiveness of compression therapy in
several venous indications following the
Clinical, Etiology, Anatomy, Pathophysiology
(CEAP) classification and scoring system, and
in lymphoedema can be found in the
Consensus document published by the
International Compression Club (ICC) in

2008.8 These indications are listed in Table 1
and include clinical stages of venous disease,
treatment following phlebological interven-
tions, venous thrombosis and lymphoedema.

The compression devices used in the trials
for these indications include bandages, stock-
ings, ortheses [like Circaid™ (San Diego, CA,
USA), tubular elastic cotton sleeves like
Tubigrip™ (Mölnycke Health Care,
Gothenburg, Sweden), Tubulcus™ (INNO-
THERA CH S.A. Service Zentrum Europa, Saint
Blaise, Switzerland)], and IPC. Not all indica-
tions have been adequately studied regarding
effectiveness of compression treatment, par-
tially due to the fact that measurement out-
comes are not always easily defined or
assessed, and that they will be dictated by the
indication at study. In this Table the references
get a GRADE-label for the recommendation
(e.g. 1B, 1A), and the insertion of
weighted/graded references under a specific
column head is deducted from the original
classes mentioned on the respective docu-
ments. Also, the pressure values are rounded
to simplified ranges. Reason for this is the
known discordance between several country
specific classifications of pressure range for
stockings, and variations in definition of
expected pressure under bandages when
applied according to the manufacturers’
instructions. This Table does not distinguish
between elastic or inelastic materials. In most
trials, measurement of the delivered pressure

was not measured in vivo, neither was the
stiffness index. Duration of follow-up in RCTs
is understandably limited, variable, and not
always representative for the selected disease
progression; thus in some indications the
deducted recommendation of duration of treat-
ment are decided by consensus or by expert
opinion. An example to illustrate this fact is
compression therapy in venous disease C4a,
C4b, C5. Experimental data exist, but Clinical
Trial data are lacking; Class III medical com-
pression stockings said to deliver 30-40 mmHg
have been shown to reduce the area of lipoder-
matosclerosis (LDS) in patients with healed
venous ulcers.9 Accordingly it is also consid-
ered to improve areas of atrophie blanche and
to reduce the edema and induration in the leg
associated with these conditions. There are
experimental data supporting effectiveness of
distinct levels of compression regarding differ-
ent aspects of LDS: reduction of edema,
eczema, iron deposition, area of LDS, inflam-
mation and pain, but no RCT’s have been
found. Clinical trials evaluating compression
treatment specifically in lipodermatosclerosis
are rare, presumably due to the many possible
outcome parameters to choose from, of which
validation is not established for the specific
indication. Progression to ulceration, and pre-
vention of this by the specific compression
device is difficult to predict and so it is hard to
calculate the power needed to demonstrate
effectiveness.

Table 1. Indications for compression treatment. Reported efficacy of compression therapy stockings, bandages and intermittent pneu-
matic compression by randomized controlled trials and meta-analyses in patients with chronic venous disorders (Clinical, Etiology,
Anatomy, Pathophysiology classification), venous thromboembolism and lymphedema. Only strong grades of recommendations are
indicated: 1A and 1B. Adapted from Partsch et al., 2008.8

Indications CEAP Compression stockings Bandages IPC
Compression pressure in mmHg

10-20 mmHg 20-30 mmHg 30-40 mmHg

C0s, C1s 1B - - - -
C1 after sclero - 1B - - -
C2a,s - - - - -
C2s pregnancy 1B 1B - - -
C3 prevention 1B - - - -
C3 therapy - - - - -
C4b - - 1B - -
C5 - - 1A - -
C6 - - 1B 1A -
After procedures - - 1B 1B -
VTE prevention therapy - - - - -

1A - - - 1A
- 1B - 1B -

PTS prevention therapy - - - - -
- - 1A - -
- - - - 1B

Lymphedema therapy - - - - -
- - - 1B 1B

CEAP, Clinical, Etiology, Anatomy, Pathophysiology classification; IPC, intermittent pneumatic compression; VTE, venous thromboembolism; PTS, post-thrombotic syndrome.

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[Veins and Lymphatics 2013; 2:e7] [page 21]

Indications define the measured outcomes in
clinical trials for compression treatment in
venous disease, and unfortunately, there is
hardly any objective standard assessment
method for most outcome parameters in the
clinical classes preceding an ulcer. This is one
of the reasons why clinical trials are hard to find
in these indications. Another explanation is
that clinical progression and thus effectiveness
of compression is difficult to predict during the
relatively short time laps of a trial.

In the early stages of venous disease, like C1
and C2, subjective symptoms are not always
present, they are not always specific nor diag-
nostic, and clinical progression is unlikely to be
influenced by compression treatment of a trial
duration. Side-effects of compression may be
considered as secondary outcome, but then
these would not be correlated to the clinical
stage of disease. For venous edema C3, symp-
toms and signs may be measured although there
are many different ways to do this. Several trials
have demonstrated edema reduction with the
use of bandages and stockings, but have not
been withheld in the abovementioned publica-
tion (Table 1).8 As mentioned in Table 1, com-
pression treatment has been positively evaluat-
ed in C5 for the prevention of ulcer recurrence,
as compared to surgery. Most clinical trials have
been performed on C6, venous ulceration, evalu-
ating wound healing as a primary outcome
parameter. This is an objectively measurable
outcome, and compression materials or applica-
tion methods can be compared for effectiveness.
Prevention of recurrence has been studied as
well, as mentioned earlier. Disease specific qual-
ity of life issues have also been evaluated, in
contrast to resolution of skin changes for which
no clinical trial could be found. The problem
here is that dosimetry and characteristics of the
compression therapy are debatable, due to out-
dated or confusing definitions and classification
of bandages or stockings. Indeed, new insights
in the physiological effects of compression treat-
ment and updated consensus documents invite
us to re-interpret older trial data. This fact
relates to the intervention itself. Another consid-
eration is that methodology of selected clinical
trials fulfils historical quality requirements. But
expectations and quality criteria become more
stringent over the years (the rules of the game
change while playing). Also, good trial-methods
do not necessarily guarantee a correct diagnosis
or scoring/grading of the clinical disease at
study. This will of course apply to the systematic
reviews or guidelines and consensus documents
derived from these trials. That fact can be named
the inherent tragedy of initiatives like the
Cochrane database and many other institutions
gathering evidence and knowledge: a RCT per-
fectly meeting today’s strict requirements may
be outdated and rejected in a later systematic
review as soon as new insights change the rules.

New insights in compression
treatment

Interpretation of the trial results and the rec-
ommendations issued from it, are very much
dependent on the above listed issues and
insights, which themselves have been the topic
of several recent consensus documents.5-7

In this issue several other contributions
debate the stiffness or elasticity of compres-
sion materials and the measured physiological
effects on the treated limb.

Properties of compression bandages have
been updated in a publication reviewing the
practical aspects and definitions.6 In that arti-
cle the acronym PLACE is proposed to summa-
rize the essential aspects that impact on the
pressure and stiffness of compression materi-
als. These are the sub-bandage pressure range
measured at the gaiter area, the number of lay-
ers (and the way they overlap), the several
components of the bandage each with its own
function (like padding, protection, retention,
compression), and the elastic properties or
behavior of the assembled bandage. This is
why pressure and stiffness must (also) be
measured in vivo, on the treated limb.

Appropriate selection and use of these four
properties will define the compression treat-
ment characteristics and effectiveness in the
several indications. The term dosimetry of
compression pressure has been proposed to
describe this.

In past clinical trials on compression treat-
ment for venous and lymphatic disease, little is
known about dosimetry of the applied com-
pression, for how long and at what level it was
or should be applied to yield the described
results. The different effects of elastic versus
inelastic or short-stretch compression are also
little understood without considering the prin-
ciple of stiffness and the resulting dynamic
behavior of the compression device, which is
rarely discussed in most selected trials and
reviews.

RCTs using out-dated definitions and classi-
fications of materials have led to systematic
reviews and recommendations based on the
same misunderstanding; it is left to the alert
reader to interpret their results with caution.
The pressure-range classifications of bandag-
es and stockings are country specific, and so
are the brands and trade names. There is yet
no universally accepted standard terminology
or classification, application technique or
methodology to apply compression treatment.
The number of publications is steadily growing
with research data, but there is no universal
estimation of pressure- values in vivo (which
is dependent of the material used, the care
giver, and the patient), and therefore there is
no consensus yet on the required pressure,

stiffness or compression technique to obtain
results in specific indications.

The abovementioned considerations may
provide part of the explanation for the wide
variability in the materials and methods sec-
tion of the several RCTs. Sound description of
the dosimetry must include components, dura-
tion, pressure, layers, elasticity, stiffness, all
aspects for which internationally accepted def-
initions are recently published, but not imple-
mented yet, and thus not used in older trials.
There is an impressive choice of compression
materials and techniques like bandages, stock-
ings, ortheses, intermittent pneumatic com-
pression devices, and combinations of all
these. As for the duration of compression ther-
apy, this may be sustained, with or without
changes during the day, or it may change over
time, possibly in a cross-over study design. Of
course, the applied pressure values or com-
pression classes must be explicitly mentioned,
referring to the methods for the in vivo assess-
ment of pressure and stiffness. Blinding can-
not be done for the application, but must be
used for outcome assessment.

Practical problems abound when consider-
ing clinical trials on compression treatment for
chronic venous leg ulcers: even if investigators
do manage to agree between centers on a stan-
dardized protocol regarding materials and
techniques, there is still a wide variation in
the limbs under study, and there are many pos-
sible outcome parameters to test, which are
not always under control or not always objec-
tively measurable. Due to the variability of
limb morphology, mobility, underlying (co-)
morbidities and ulcer etiology, response to
treatment will remain an individual character-
istic confounding baseline comparability of
studied subjects.

Nevertheless, as stated in almost all guide-
lines and systematic reviews, it is probably
true to conclude that to heal a venous leg ulcer
(C6), management that includes compression
is more effective than without compression,
that higher pressure (stiffness?) is more effec-
tive than low pressure values, and that com-
pression should stay in place as long as possi-
ble. It is unclear if this means sustained pres-
sure by elastic systems or pressure peaks
under inelastic bandaging systems or stiff
stockings. Some reviewers also recommend
applying the highest pressure tolerated by the
patient, although this may negatively influ-
ence compliance/adherence to treatment, and
secondly, this statement has been refuted by
recent trials in secondary lymphedema, which
strongly suggest that there is a window of opti-
mal pressure values for achieving edema
reduction. The same may be true for ulcer
healing, effect on skin changes, inflammation,
or subjective symptoms.10

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Conclusions

In order to compare the effectiveness of
compression systems and materials, modern
terminology (for which consensus exists) shall
be used to describe the materials applied, and
objective measurement of the dosimetry (pres-
sure/stiffness/dynamic behavior/duration) is
an added value in future trials and systematic
reviews. Recommendations to guide clinicians
and researchers hereby have been reported by
consensus working groups.11 The methodologi-
cal validity and quality of selected previous
RCTs remains, but we may have to re-interpret
the results in the light of new insights which
have challenged myths and dogmas10 concern-
ing hemodynamic effects of elastic and inelas-
tic compression treatment, and concerning
pressure and stiffness, the characteristics of
the final compression system more than those
of the individual components used.

References

1. European Committee for Standardization
(CEN). Medical compression hosiery. ENV
12718:2001 E, August 2001. Brussels:

European Committee for Standardization;
2001. Available from: www.cenorm.be/
catweb/; www.cen.eu

2. RAL-GZ 387. Deutsches Institut für
Gütesicherung und Kennzeichnung
Medizinische Kompressionsstrümpfe RAL-
GZ 387. Neufassung Sept 2000. Berlin:
Beuth-Verlag; 2000. Updated in: RAL GZ
387 for compression stockings:
Gütezeichengemeinschaft Medizinische
Kompressionsstrümpfe; January 2008.
Available from: http://www.gzg-kompres-
sionsstruempfe.de/

3. British Standards Institution. Specifi -
cation for the elastic properties of flat,
non- adhesive, extensible fabric bandages.
BS 7505:1995. Updated: January 2011.
Available from: http://www.standardscen-
tre.co.uk/bs/BS-7505-1995/?s=1

4. Guyatt G, Gutterman D, Baumann MH, et
al. Grading strength of recommendations
and quality of evidence in clinical guide-
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2006;129:174-81.

5. Clark M. Compression bandages: princi-
ples and definitions. In: European Wound
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of the European Wound Management

Association. Frederiksberg: Medical
Educational Partnership Ltd; 2003.
Available from: http://www.ewma.org

6. Partsch H, Clark M, Mosti G, et al.
Classification of compression bandages:
practical aspects. Dermatol Surg 2008;
34:600-9.

7. Partsch H, Clark M, Bassez S, et al.
Measurements of interface pressure and
stiffness. Dermatol Surg 2006;32:224-33.

8. Partsch H, Flour M, Coleridge Smith P, et
al. Indications for compression therapy in
venous and lymphatic disease. Consensus
based on experimental data and scientific
evidence; Under the auspices of the IUP.
Int Angiol 2008;27:193-219.

9. Vandongen YK, Stacey MC. Graduated
compression elastic stockings reduce lipo-
dermatosclerosis and ulcer recurrence.
Phlebology 2000;15:33-7.

10. Flour M, Clark M, Partsch H, et al. Dogmas
and controversies in compression therapy:
Report of an International Compression
Club (ICC) meeting, Brussels, May 2011.
Int Wound J 2012. [Epub Ahead of Print].

11. Rabe E, Partsch H, Jünger M, et al.
Guidelines for clinical studies with com-
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