Abstract
Chronic venous disease (CVD) is one of the most common adult conditions, comprising any long-term morphological and functional abnormalities of the venous system that are manifested either by symptoms and/or signs indicating the need for investigation and/or care [1–3]. Chronic venous insufficiency (CVI), representing advanced CVD, is classified by functional abnormalities of the venous system producing edema, skin changes or venous ulcers [3]. According to the clinical, etiological, anatomical and pathological elements classification system, CVI is represented by clinical, etiological, anatomical and pathological elements classes C3–C6 [3]. Although data vary widely, the prevalence of CVI in the western world is estimated to be up to 40% in females and up to 17% in males [1,2].
Medical compression stockings (MCSs) represent the cornerstone of conservative treatment for patients with CVI [4]. Based on data from the Bonn Vein Study, 51.4% of all adult patients (n = 3072) recruited between November 2000 and March 2002 received no treatment for venous disease, and compression stockings were the most commonly prescribed treatment in the overall population (14.6%; males: 7.5%; females: 20.3%) [5]. MCS prescriptions increased with increasing patient age and with increasing severity of venous disease.
Despite the fact that MCSs are the most common treatment option for patients with CVD, a large proportion of CVD patients remain non-compliant with compression therapy [6]. Non-compliance is a major cause of treatment failure and it also generates healthcare expenditure [7]. Despite intensive patient education and ongoing monitoring through dedicated programs, noncompliance rates remain high, suggesting that other factors are responsible for noncompliance [8–10]. There are a number of well-documented reasons for MCS nonuse [7,11,12]; based on US data from more than 3000 new CVD patients, the main reasons for MCS nonuse included patient perception that the stockings did not help (14%), binding/‘cutting off’ the circulation (13%), too hot to wear (8%), unable to apply without help (2%), limb soreness (2%), itching (2%), poor cosmetic appearance (2%) and cost (2%) [7,11].
An assessment, presented and published by the American Venous Forum, showed that any product that improves the donning of compression stockings, making it easier to put them on/take them off, would significantly improve compliance rates and efficiency [13]. Indeed, of 126 patients surveyed, almost 30% of the patients stopped wearing compression stockings due to difficulties in putting them on [13]. Based on the findings of Raju and colleagues, comfort is also a key factor in noncompliance, with ‘wear/comfort’ factors and ‘intangible sense of restriction imposed by the stockings’ being the two interdependent major noncompliance categories [7].
Conventional MCSs provide a decreasing pressure profile from distal to proximal (degressive gradient). Recently, a new concept in MCSs has become available, namely progressive (or inversely graduated) compression stockings, which provide a higher pressure at the calf than at the ankle region [14].
The objective of the current survey was to compare the difficulty associated with putting on/removing two different compression stockings; a conventional degressive compression stocking and a progressive compression stocking.
Patients & methods
The survey was conducted among women in France in 2012 (during spring), recruited by an independent pooling institute (CSA Health Institute, Paris, France) through pharmacies, as purchasers of physician-prescribed C3 compression stockings in the past 3 months. To ensure a homogeneous sample, only patients using C3 stockings were recruited. In order to obtain a representative patient sample, the study aimed to recruit approximately 200 women from a wide geographical population in approximately 20 cities in ten regions across France. In the situation where a woman who met the inclusion criteria did not want to participate in the survey, another woman was asked to participate (via the same pharmacy and as a purchaser of physician-prescribed C3 compression stockings). Patients were asked to complete a questionnaire that was designed to evaluate their experience with putting on/taking off compression stockings. In order to reflect real life, daily conditions of a patient wearing compression stockings, the study was conducted in the patient's home; study investigators (who were fully trained on how to measure and assess patients, and could provide accurate stockings based on patient measurements) visited each patient at home.
All patients provided informed consent and were randomized to two groups: group 1 assessed stocking A on the right leg, then stocking A on the left leg (control group); group 2 assessed stocking A on the right leg, then stocking B on the left leg.
Randomization was performed using boxes (stocking A/stocking A or stocking A/stocking B) that were prepared before the survey commenced. Stocking A was a conventional C3 degressive compression stocking (Pierre Fabre Laboratories, France), composed of polyamide, cotton and elastane, with an ankle pressure of 24–28 mmHg and residual pressure in the calf (50–80% of the pressure at the ankle; 14–18 mmHg). Stocking B was a progressive compression stocking (Progressiv N'System, Pierre Fabre Laboratories) composed of polyamide and elastane, exerting higher pressure in the calf (21–25 mmHg) than in the ankle (8–12 mmHg).
Stocking pressure ranges were determined in vitro according to the French standard NF G 30–102b (on a dynamometer). Both stocking types were supplied as ‘off-the-shelf’, round-knitted knee-highs and were available in four sizes. Each of the groups was blinded with regard to the stocking type that the other group was assessing; in addition, the investigators were blinded to the origin/nature of the stocking types. A statistician from an independent company (ClinSearch, Bagneux, France) managed the random allocation of stockings; a separate statistician (Pierre Fabre Laboratories) analyzed the data.
Immediately after putting on/taking off each of the stockings (duration of use ≤10 min), patients completed the survey, which consisted of three parts: part one: provide an overall score for their current stockings (‘compression stocking score’), and complete the questionnaire for their current stockings; part two: provide an overall score for stocking A on the right leg, and complete the questionnaire for this stocking; and part three: provide an overall score for stocking A or B (according to their assigned group) on the left leg, and complete the questionnaire for this stocking.
The predefined primary objective of the survey was to assess the ‘ease of putting on/taking off’ between two different compression stockings. The main evaluation criteria was the global score difference between stocking A and B.
At the start of the evaluation, patients also provided information relating to sociodemographic parameters, comorbidities, lifestyle/exercise and family history of varicose veins.
Questionnaire
The design of the questionnaire (
From the patient perspective, ‘insertion of the foot’, ‘rolling onto the leg’, ‘fragility’, ‘putting on’ and ‘time to put on’ appeared to be the most important concepts in the daily life of compression stocking users. Items such as ‘comfort’ and ‘feel’ (transparency, thinness, color and how they feel to the touch) also seemed to guide patient choice. On the other hand, from a healthcare professional's point of view, physicians advised that the questionnaire should consider main technical concepts such as ‘resiliency’, ‘putting on’ and ‘taking off’. Pharmacists, who are in direct contact with patients, identified stocking ‘color’ and ‘fragility’ as key issues for users.
Subsequently, 12 items covering all of the domains were selected for inclusion in the questionnaire. Simple and comprehensive questions were generated. Patient opinion on compressive stockings was captured using visual numeric scales, from 0 to 10 (0 = very unacceptable/very difficult; and 10 = very good/very easy).
To highlight the underlying constructs through these items, an explanatory factor analysis (principal-axis factoring method) of data from compressive stockings currently used by the patients was performed. Since correlations between latent traits may exist, an oblique promax rotation after an orthogonal varimax rotation was chosen. The most parsimonious model yielded to two factors with a correlation coefficent, r, of 0.55 (p < 0.0001). These two dimensions, called ‘ease of putting on’ and ‘comfort’, included seven (questions 2–8) and four (questions 9–12) items, respectively. These two dimensions were named in this manner based on the questions loaded on each factor; moreover, the survey had a ‘comfort’ dimension in concordance with previous study findings [7]. These two dimensions had a high internal consistency (Cronbach's a > 0.84), as did the overall questionnaire (a = 0.90). The item ‘how the stocking feels to the touch’ was highly cross-loaded on both factors and, subsequently, was removed from the questionnaire. In order to make it easier to compare between dimensions, dimension scores were calculated by adding up each individual item score and then transforming them onto a 0–100 scale. A global score, the sum of all individual item scores, was also transformed onto a 0–100 scale.
Statistical analysis
The survey sample size was determined based on the perspective, from experts in sensory analysis, that a minimal difference of seven units on the global score (ranking from 0 to 100) between the two stockings could be considered as significant. Assuming an a priori unknown standard deviation of 20, a power level of 95% and an α-risk fixed at 5% in a one-sided test, we determined that 90 individuals completing both questionnaires was the necessary sample size. Assuming 10% missing data, approximately 100 subjects were required for inclusion in group 2. For randomization blinding reasons, 100 subjects were also required in the other arm.
Study variables are presented as mean values, standard deviation and median for quantitative variables and numbers of subjects with percentages for categorical variables.
For categorical variables, intergroup comparisons were performed with the χ2 test or Fisher's exact test. Comparisons between groups were performed using the Student's t-test or the Wilcoxon and Mann–Whitney test for quantitative variables. Intragroup comparisons of scores were performed with paired Student's t-test or signed rank Wilcoxon U test when the conditions necessary for the application of this test were not met. The level of significance was set at 5%. Data were analyzed using SAS® software version 9.3 (SAS Institute Inc., NC, USA) on Windows hardware.
The following subgroup analyses were conducted as secondary end points: patients who did not wear stockings daily due to difficulty in putting them on/taking them off; patients with osteoarthritis; obese patients; and unemployed patients.
Results
Patient demographics
A total of 222 French women were originally included in the study. However, two patients did not provide responses to all of the survey items, so were excluded from the final analysis. Therefore, the final survey analysis included 220 evaluable French women (group 1: n = 102; group 2: n = 118). Baseline sociodemographic data are presented in
Baseline demographic data for 220 French women included in the survey to assess physician-prescribed medical compression stockings.
One patient reported osteoarthritis without specifying type; counted as missing data (n = 1).
SD: Standard deviation.
With regard to baseline characteristics, patients in both compression stocking groups were well balanced; with the exception of cardiovascular disease (present in 39.2% of group 1 patients vs 23.9% of group 2; p = 0.0148), there were no statistically significant differences in patient characteristics between groups 1 and 2 (
Difficulty associated with putting on/taking off stockings
As shown in
Results from questionnaires completed by 220 women in France who assessed physician-prescribed medical compression stockings.
‘Ease of putting on’ and ‘comfort’ dimensions included seven (questions 2–8) and four (questions 9–12) items, respectively (see Supplemntary material [www.futuremedicine.com/doi/suppl/10.2217/WHE.13.13] for full questionnaire). Global score represents the overall score from the two dimension scores, transposed on a 0–100 scale.
According to Cohen, effect sizes are considered as follows: small effect size: d = 0.20; medium effect size: d = 0.50; and large effect size: d = 0.80 [15].
SD: Standard deviation.
On the contrary, patients in group 2 reported significantly better experience in dimension and overall scores, including the ‘putting on/taking off’ and ‘comfort’ dimensions, with the progressive stockings compared with the degressive stockings (
Differences in individual visual numeric scale scores between the right and left legs were also all statistically significantly greater for group 2 patients; in comparison, group 1 (control) patients showed no improvement in individual visual numeric scale scores (
Subgroup analyses
Subgroup analyses conducted in patients with osteoarthritis (n = 105), obesity (n = 57), those who do not wear their stockings everyday due to difficulties putting them on/taking them off (n = 54) and unemployed patients (n = 112).
‘Ease of putting on’ and ‘comfort’ dimensions included seven (questions 2–8) and four (questions 9–12) items, respectively (see Supplementary material [www.futuremedicine.com/doilsuppl/10.2217/WHE.13.13] for the full questionnaire). Global score represents the overall score from the two dimension scores, transposed on a 0–100 scale. Data are presented as mean (standard deviation) differences and median differences.
Discussion
The current survey, conducted in more than 200 representative French women, clearly demonstrates that, compared with a conventional degressive MCS, the progressive MCS was superior in all parameters that were evaluated, including dimensions of comfort and ease of putting on/taking off. Patients scored all individual survey parameters significantly higher for the progressive stocking compared with the conventional compression stocking. By contrast, patients who evaluated the conventional degressive stocking on the right leg then the left leg (controls), showed no significant between-leg differences.
Compression is one of the mainstays of management in venous disorders of the leg and continues to be the standard of care for patients with advanced CVD and venous ulcers (C3–C6) [16]. Nevertheless, noncompliance remains one of the largest obstacles to the effective use of MCSs. Compression stocking noncompliance was reported to be very high in 3144 patients in the USA with CVD, regardless of age, sex, CVD etiology, duration of symptoms or disease severity [7,11]. While the problem of noncompliance is well known, the subject of how to improve compliance with MCSs has been debated widely [17].
Putting on/taking off MCSs is often one of the leading factors in patient noncompliance [18]. A random sample of 40 phlebologists in France reported factors likely to limit their patients (n = 320) from donning compression stockings. Almost 20% of these patients were reported to experience significant difficulty when putting on their elastic compression stockings. Moreover, a factorial analysis showed that the patients who had the most difficulty donning compression stockings were those who had the greatest requirement to use compression stockings [18].
Therefore, compression stockings that provide improved ease of putting on/taking off and comfort should help to improve patient compliance and, thus, improve treatment effectiveness. Results from the current survey support the observation that difficulty associated with stocking comfort and ‘putting on/taking off’ compression stockings are concerns for patients and that, compared with the conventional degressive stocking, use of the progressive stocking significantly improved the comfort and ease of putting on/taking off.
Furthermore, each patient subgroup that was evaluated also reported significantly improved experience with the progressive stocking compared with the classic stocking. The general health of patients is associated with difficulty putting on/taking off compression stockings [7]; patients in our subgroup analysis were experiencing health factors that could be associated with a greater degree of difficulty in donning compression stockings, namely osteoarthritis or obesity. The largest subgroup of patients analyzed in our study were those not in gainful employment (n = 112); it has been reported elsewhere that high cost is a factor in patient noncompliance with the use of compression stockings [12]. Regardless of subgroup type, patients in our study reported significantly better scores in all domains of the questionnaire, including putting on/taking off stockings and stocking comfort.
The current study has a number of limitations. First, the study was conducted only in women. Therefore, it is not possible to draw conclusions on the effects of different stocking types on the difficulty of putting on/taking off MCSs in males; however, females represent the majority of patients who are prescribed MCSs for chronic venous disorders [19], and the current study was designed to assess a representative, everyday female population in France. With regard to the size of the patient population surveyed in the study, with 220 responses the sample size of the survey is clearly limited. Additionally, with surveys of this nature there is potential for selection bias to influence the results [20,21]. Nevertheless, one of the key strengths of the current survey is that it captures responses from representative patients who are using physician-prescribed compression stockings under ‘real life, everyday’ conditions. Other limitations include the fact that respiratory insufficiency was not assessed in the questionnaire, but as for other comorbidities (with the exception of more patients with cardiovascular disease in the control group), the assumption is that a similar proportion of patients in both groups had respiratory insufficiency; progressive stockings were only assessed on one leg, but there were no significant differences in each group between the right leg and left leg (
Conclusion & future perspective
In conclusion, the current study demonstrates that, over a short time period, the progressive medical stocking is associated with significantly better outcomes (ease of putting on/taking off and comfort) than the conventional compression stocking. Future large studies evaluating compliance rates with the progressive medical stocking are warranted, in order to assess whether the long-term use of progressive compression stockings is associated with anticipated improved patient compliance and, consequently, improved effectiveness in the management of CVD.
Executive summary
The aim of this study was to assess the difficulty associated with putting on/taking off and comfort of two different medical compression stockings (MCSs); a conventional degressive MCS and a progressive MCS.
Two hundred and twenty French women, identified as wearers of physician-prescribed class III MCSs in the past 3 months, participated in the study.
A questionnaire, administered by fully trained study investigators at each patient's home, was completed after patients randomly evaluated either: a degressive MCS (right leg, then left leg; group 1, controls) or a degressive MCS (right leg) then a progressive MCS (left leg; group 2).
Patients in the control group (degressive stocking on the right leg, then on the left leg) reported no significant differences in any of the questionnaire parameters.
All individual survey items were significantly improved with the progressive MCS compared with the degressive MCS.
Compared with the degressive MCS, the progressive MCS was associated with significantly improved ease of putting on/taking off and comfort.
Footnotes
The survey was funded by Pierre Fabre Laboratories (France). JP Benigni has received fees for his participation in the conception of the study and the analysis of the results. S Branchoux, I Bacle and C Taieb are employees of Pierre Fabre Laboratories. The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed.
The authors thank DP Figgitt, Content Ed Net, for providing valuable editorial assistance in the preparation of this manuscript; editorial assistance was funded by Pierre Fabre Laboratories.