A Meta-analysis to Compare Four-layer to Short-stretch Compression Bandaging for Venous Leg Ulcer Healing

Compression therapy is the standard of care for venous leg ulcers (VLUs), and some evidence suggests 4-layer compression is more effective than short-stretch bandages. A meta-analysis was conducted to compare the effectiveness of these 2 compression bandages for venous ulcer healing. In March 2016, a systematic review of the literature was conducted to identify randomized controlled trials.Databases used included Pubmed/MEDLINE, EMBASE, Cochrane Central, the Cumulative Index of Nursing and Allied Health Literature, and the Latin American and Caribbean of Health Sciences Information System. Search terms were varicose ulcer, venous leg ulcer, venous ulceration, leg ulcer, compression bandages, compressive therapy, multilayer system, four-layer system, elastic bandages, short-stretch bandage, short-stretch system, and inelastic bandage. No publication time or language restrictions were imposed, but findings subjected to analysis were limited to results of research that reported healing and healing time using 4-layer and short-stretch compression only. The quality of the studies was assessed using the Jadad scale. Data extracted included study design, country, target population demographics, VLU clinical aspects at baseline, sample size, interventions applied, follow-up period, complete healing, and healing time as outcomes. Relative risk was calculated considering a 95% confidence interval for dichotomous variables (complete healing), and heterogeneity was statistically assessed among the studies using the chi-squared test assuming random effect when I² ≥50%. The search yielded 557 papers; 21 met the study criteria for full-text analysis, and 7 met the meta-analysis inclusion criteria. The studies included 1437 patients, average age 70 (range 23–97) years with 1446 venous leg ulcers. Most (5) studies were classified as being at low risk of bias. At 12 and 16 weeks, 259 ulcers (51.08%) healed completely in the 4-layer and 234 (46.34%) in the short-stretch bandage groups, respectively (P = .41). At 24 weeks, 268 ulcers (69.07%) in the 4-layer and 257 (62.23%) in the short-stretch bandage groups, respectively, had healed (P = .16). The 2 bandage systems evaluated were similar in achieving complete healing at their respective study endpoints. The average time for healing was 73.6 ± 14.64 days in the 4-layer and 83.8 ± 24.89 days in the short-stretch bandage groups; no meta-analysis was done for this outcome due the inability to retrieve all the individual patient data for each study. The choice of compression system remains at the discretion of the clinicians based on evidence of effectiveness, patient tolerability, and preference. Additional randomized controlled trials to compare various wound and patient outcomes between different compression systems are warranted. 

Venous leg ulcers (VLUs) usually affect the lower part of the leg near the medial malleolus, are associated with venous hypertension, and represent the most advanced stage of chronic venous insufficiency. Due to its high level of morbidity, leg ulcer treatment places a heavy burden on public and private health care service.^1-3 

In a retrospective study⁴ that analyzed 250 patients with a history of VLU, the recurrence rate was 55% at 12 months after the ulcer had healed. The prolonged time of treatment and rehabilitation of individuals affected with VLU generates a high cost both for the patient and the health care system.⁵ A 2015 systematic review⁶ showed that in the United States alone, $3.5 billion is spent on VLUs annually. The choice of treatment directly affects wound development and healing and should avoid complications such as infection and reduce pain, subsequently improving patient quality of life and optimizing cost effectiveness, which are of high importance for both the patient and the health care institution.^7,8 An Australian  retrospective study⁹ concluded that when evidence-based guidelines are not implemented properly, the healing outcome is compromised. It is in this context the health care provider must demonstrate and apply scientific knowledge to provide effective, evidence-based treatment for this type of wound while considering patient individuality.^3,10  

Compression therapy is the standard of care for VLU; it is recommended for all patients with VLUs with an ankle brachial index (ABI) >0.8.3 Many compression devices are available; it is the responsibility of the health care provider to properly assess and choose the most suitable type of compression therapy for the patient.^11-13 The type of compression device chosen should be based on evidence of effectiveness, clinical assessment, patient preference and tolerance, and the health care provider’s technical skills.³

The most recent Cochrane systematic review update¹³ (2012) reported a multicomponent bandage system (4-layer bandage [4LB]) is more effective for the management of VLUs than short-stretch bandages (SSBs); patients using the 4-layer bandage healed faster. More evidence has been published since this review was prepared. The purpose of the current study is to determine whether the Cochrane report conclusion is still accurate.  

To guide this review, the following question was formulated based on the patient-population-problem, intervention, comparison, outcome research strategy: Does a 4LB system provide superior healing rates in comparison to SSBs in patients with a VLU? In this context, the main objective of this review was to compare the effectiveness of the 4LB to the SSB by using VLU complete healing and healing rate data obtained from randomized controlled trials.

The literature search was performed in March 2016 by 2 independent reviewers using PubMed/MEDLINE, EMBASE, the Cumulative Index of Nursing and Allied Health Literature (CINAHL), Cochrane Central, and the Latin American and Caribbean of Health Sciences Information System (LILACS). The search terms used were varicose ulcer, venous leg ulcer, venous ulceration, leg ulcer, compression bandages, compressive therapy, multilayer system, four-layer system, elastic bandages, short-stretch bandage, short-stretch system, and inelastic bandage. No language or date of publication restrictions were imposed. The search strategy for each database is listed in Table 1. 

Inclusion criteria stipulated that articles selected for assessment needed to describe randomized controlled trials that compared a 4LB system with SSBs for VLU healing. Studies that compared bandages with zinc paste, elastic stockings, bandages with fewer layers, and Unna boot, as well as nonrandomized or cost analysis studies, were excluded. Outcomes evaluated were healing time and number of ulcers completely healed, where healing was defined as full epithelialization and no drainage.

Study quality was assessed by 1 of the authors using the Jadad scale.¹⁴ The studies were evaluated regarding study design, blinding, and loss of participants to follow-up. Points were assigned to reviewed studies as follows: 2 points if the study was properly randomized, 2 points when blinding was done correctly, and 1 point when the authors reported withdrawals and dropouts. The studies were scored using a range of 0 to 5 (where 0 is the weakest and 5 is the strongest). A score <2 indicated poor methodological quality.

Study data were summarized in a data extraction form by 2 of the researchers and included study design, country, target population, age, gender, ABI, sample size, interventions applied, follow-up period, withdrawal and/or lost of follow-up,  complete healing, and healing time as outcomes. 

For analysis of the dichotomous variables (complete ulcer healing), the relative risk (RR) was calculated considering a 95% confidence interval (CI). A subgroup analysis was considered when there were different endpoints for complete healing assessment. Studies that reported complete healing rates at 3 to 4 months were analyzed separately from the studies that reported results at 6 months.

Heterogeneity was statistically assessed using the chi-squared test assuming random effect when I² ≥50%. Software Review Manager (RevMan), version 5.3 (The Nordic Cochrane Centre, Copenhagen, Denmark) was used to perform statistical analysis.

After deleting duplicate studies and evaluating the titles and abstracts, 21 studies were selected for review. Of those, 7 met the inclusion criteria for this study; 14 were excluded because the products were not the 2 stipulated for comparison and/or they were nonrandomized or cost-effectiveness studies (see Figure 1). Most (5) studies (71.4%) were done in Europe,^15-19 1 was published in Asia,²⁰  and 1 in North America²¹ (14.3% each). All were published in English. 

Table 2 summarizes the main findings of the studies included in this review. 

The studies’ follow-up period ranged from 12 to 60 weeks, and the endpoint for complete healing outcome was reported at 12 weeks in 3 studies,^16,17,21 at 16 weeks in 1 study,¹⁸ at 24 weeks in 4 studies,^15-16,19,20 and at 60 weeks (420 days) in 1 study.²¹ The healing time of the VLUs using 4 layers was between 47 and 113 days and for the SSB group was between 43 and 157 days. 

Table 3 describes the methodological evaluation through the results of Jadad  scale. 

All studies were randomized clinical trials; 2 studies^19,20 failed to describe the method used for randomization. Six (6) studies^15-20 failed to blind the participant or the observer. Only 1 study²¹ was able to achieve the maximum Jadad scale score (although the participants were not blinded, the observer was). Two (2) studies^19,20 were considered to have poor methodological quality (Jadad score = 2). 

The 7 studies analyzed included a total of 1435 patients, 657 (45.78%) male and 778 (54.48%) female, average age 70 (range 23–97) years, with 1446 ulcers, 720 ulcers treated using 4LB and 726 using SSB. All patients had been diagnosed with venous disease and had an ABI  >0.9 mm Hg. The population of each study was considered homogeneous at baseline according to their respective authors. Complete healing occurred in 441 (61.25%) of ulcers in the 4LB group and in 422 ulcers (58.13%) in the SSB group. Healing time was reported in 5 studies and averaged 73.6  ± 14.64 days and 83.8 ± 24.89 days for ulcers treated with 4LB and SSB, respectively. It is important to mention that no meta-analysis was done for this outcome because the reviewers were unable to retrieve  individual patient data from each study, making it impossible to calculate the hazard ratio (HR). 

Complete healing was reported in 4 studies^16-18,21 at 12 or 16 weeks and in 4 studies^15,16,19,20 at 24 weeks of follow-up (see Figure 2). The VenUs I Study¹⁶ reported the outcome complete healing at 12 and 24 weeks. Meta-analysis showed that at 12 or 16 weeks, 259 (51.08%) ulcers healed completely in the 4LB group versus 234 (46.34%) in the SSB group (RR: 1.07 [95% CI; 0.91-1.27]; P = .41). At 24 weeks, 268 ulcers (69.07%) in the 4LB group and 257 (62.23%) in the SSB group completely healed (RR: 1.13 [95% CI; 0.95-1.34]; P = .16). Forest plot chart analysis showed no superiority in outcomes between the 2 bandage options; both bandages yielded similar complete healing rates. 

The Cochrane review¹³ published in 2012 compared 4LB and SSB; it included 5 studies, analyzed 797 ulcers, and reported the risk ratio (RR) for complete healing as 0.96 [0.88, 1.05]; P = .34. The current review included 7 studies, analyzing 1446 ulcers, with the RR for complete healing at 12 to 16 weeks of 1.07 (95% CI; 0.91-1.27; P = .41) and at 24 weeks of 1.13 (95% CI; 0.95-1.34; P = .16). Therefore, current meta-analysis reinforced the similarity in the ability of both types of compression to achieve complete healing. 

The average time for healing in this analysis was 73.6 ± 14.64 days for ulcers treated with 4LB and 83.8 ± 24.89 days for those provided SSB. Similar results were found in the Cochrane review,¹³ where the average time for healing was 90 days and 99 days for the 4LB group and SSB group, respectively. 

Because the 4LB group achieved slightly faster healing, the Cochrane review¹³ concluded it was a statistically significant result. (HR 1.32 [1.09, 1.60]; P = .0039). However, another review²² that included 6 trials and 1168 ulcers that analyzed the same outcomes found no statistical difference in time to healing between the 2 types of compression (HR 0.88 [95% CI; 0.76-1.6]; P = .08). These results oppose the findings of the current review and the Cochrane review¹³ regarding time to healing. 

When the concern is the need to apply ideal pressure for improving the functioning of the calf pump, both bandage systems provide the pressure recommended by the Wound Ostomy Continence Nurses’ Algorithm for treatment of VLUs.²³ If the consideration is utilizing a system that provides higher pressures when patients are in a vertical position, a review²³ comparing the types of bandages available for treating VLUs found that a low elasticity system presents a major advantage by providing high pressure while walking and low pressure during rest in order to counteract the high hydrostatic pressure in the veins.²⁴ 

Regardless of the compression system chosen, the expertise of the health care provider and the ability of the patient to tolerate the compression are crucial factors for achieving good outcomes using compression therapy.^9,18,21

Although no restriction was imposed regarding language or date of publication, the search results may have inadvertently not included studies that upon further research (eg, exploration of study citations) may have provided additional information. This current review did not facilitate inclusion of the HR estimate for time to healing because the reviewers were unable to retrieve the individual patient data for each included, nor did it include other important outcomes, such as reduction of wound size/area and quality of life. Although all of the 7 studies analyzed were randomized controlled clinical trials, 2 failed to describe the randomization method used and the method for blinding,^19-20 which resulted in a low score on the Jadad Scale, owing to high probability of bias (total score <2). Moreover, it must be taken into consideration that in an interventional study where the bandage types differ substantially from each other and where inevitably the participant notices which type of bandage has been applied, blinding of the parties involved (participant and health care provider) is challenging to achieve.

A meta-analysis of 7 randomized controlled clinical trials (most classified as being at low risk of bias) that compared use of 4LB and SSB in terms of VLU healing showed no significant differences in the proportions of ulcers healed after 12 to 16 weeks (RR: 1.07 [95% CI; 0.91-1.27]; P = .41) or 24 weeks (RR: 1.13 [95% CI; 0.95-1.34]; P = .16). The choice of compression therapy remains dependent on the evaluation and professional skills of the health care provider, in addition to its tolerability and patient preference. More randomized controlled trials are needed to assess healing rates and healing time to determine which compression system offers the best results for the patients with VLUs.

Ms. De Carvalho is a wound care nurse and Mr. Peixoto is a registered nurse, Antonio Pedro Hospital; Ms. Silveira is an intensive care nurse and a PhD Student, Academic Program in the Health Care Sciences Department; and Ms. Oliveira is a PhD Professor, Academic Program in the Health Care Sciences Department, Federal Fluminense University, Rio de Janeiro, Brazil.

Please address correspondence to: Magali Rezende De Carvalho, RN, MSN, CWOCN, Federal Fluminense University, Rua Dr. Celestino, 74 – Centro, Niteroi, Rio de Janeiro, Brazil 24020-091; email: magalirecar@gmail.com.