Journal of the New Zealand Medical Association, 22-May-2009, Vol 122 No 1295
Venous ulcer management in New Zealand: usual care versus guideline recommendations
Andrew Jull, Natalie Walker, Varsha Parag, Peter Molan, Anthony Rodgers; on behalf of the Honey as Adjuvant Leg Ulcer Therapy (HALT) trial collaborators
Leg ulcers are defects in the epidermis, below the knee, which are present for more than 4 to 6 weeks.1 Typically, leg ulceration is a chronic, relapsing, and remitting condition that is associated with impaired circulation. The main causal conditions are venous disease, arterial disease, diabetes, or unrelieved pressure over a bony prominence.
Venous insufficiency is the most common cause of leg ulceration, accounting for more than half of all ulcers on the lower limb and 67–70% of ulcers above the foot.2,3 The period prevalence of leg ulcers in New Zealand has been estimated at 79 per 100,000 per year,4 although capture-recapture analysis suggests a more accurate estimation is between 393 and 839 per 100,000 per year.5
In both New Zealand and overseas there is wide variation in treatments used in ulcer management, with large numbers of products employed.1,6 Research in the United Kingdom indicates that such variation remains the case even after protocol-guided care has been implemented, although the variation in product use may be reduced.7
In 2000 the first New Zealand guidelines for leg ulcer management were disseminated.8 The extent to which community-based management of venous ulcers mirrors the guideline recommendations has not been assessed. Data from the control arm of community-based clinical trial on venous ulcers offers such an opportunity.
Clinical trial—The Honey as Adjuvant Leg Ulcer Therapy (HALT) trial (ISRCTN 06161544) was a New Zealand-based pragmatic, open-label, randomised controlled trial to evaluate the effectiveness of manuka honey-impregnated calcium alginate dressings in addition to compression bandaging on venous ulcer healing compared to usual care.9 Usual care consisted of the normal range of compression systems and dressings available to the district nurses at the study centre. Participants could also receive additional treatment for their venous ulcers as clinically indicated, either from the district nurse or from other providers, such as general practitioners or hospital-based practitioners.
Participants were recruited through four district nursing services (Auckland, Counties Manukau, Waikato, and the Nurse Maude Association in Christchurch). These services were selected because they had organised leg ulcer services and provided ulcer care that was likely to be consistent with that recommended in the New Zealand Guideline for Care of People with Chronic Leg Ulcers.8
Participants were recruited between May 2004 and September 2005 and were included if they were: aged 18 years or over; able to provide informed consent; had a venous leg ulcer; had an ankle-brachial index of 0.7 or greater; were able to be treated with compression at one of the study centres; did not have diabetes, rheumatoid arthritis, or peripheral arterial disease; and were not using honey on the ulcer.
Participants had face-to-face assessments at randomisation and at 12 weeks after randomisation. During the 12-week treatment period, district nurses provided data after each visit on healing status and the resources used during the visit. Costs were calculated using the resource data and the retail cost of the products. Participants were also contacted by telephone at 6 months after randomisation to assess ulcer recurrence and stocking use. Treatment duration was until healing or for 12 weeks, whichever occurred sooner.
Guideline recommendations—Four treatments from the guideline were selected to compare practice with guideline recommendations.
These treatments represent interventions that can be reasonably assured to have an effect on cost and/or effectiveness during an episode of care (Box 1).
The treatments were:
181 participants received to usual care. The baseline characteristics of the participants by study centre are presented in Table 1.
171 (96%) participants were in multilayer compression, with 59% in four-layer compression and 36% in three-layer compression. Only 6% of participants were in single-layer systems (short-stretch or long-stretch compression). There was regional variation in preference for bandaging systems with 80% of participants in Auckland being in three-layer compression whereas 83% of Waikato participants were in four-layer compression (Table 2). Counties Manukau and Christchurch participants had compression split approximately 60:40 between four-layer and other systems.
Overall, compliance with compression bandaging (defined as being in compression for more than 75% of the district nursing visits over the 12-week treatment period) was 89%. Compliance was highest in Christchurch (98%), but similar in the remaining centres (84–85%).
The frequency of dressings used is described in Table 3. The total number of dressings used (1823) was lower than the total number of district nursing visits (2196). This difference was in the main accounted for by the fact a dressing would not be used on the final district nursing visit when a patient’s ulcer had healed.
Overall simple, moist, and medicated dressings each accounted for about one-third of dressings used. Across study centres, simple dressing use was broadly similar, but the frequency of moist and medicated dressing use varied by centre. For example, district nurses at Auckland DHB mostly used moist wound products for their patients, whereas Counties Manukau district nurses used mostly medicated products.
Within the product categories, there were also clear regional preferences with 99% of medicated dressings used in Counties Manukau being silver-impregnated, compared to 7% in Waikato and 36% in Christchurch.
The total spend on dressings was $17,191 in 2005 dollar terms. Expenditure on simple dressings was $832 (5%), on moist dressings was $6009 (35%) and on medicated dressings was $10,287 (60%).
Table 1. Characteristics of 181 participants in usual care arm by study centre*
* Values are N (%) unless otherwise stated. SD is standard deviation. ADHB is Auckland District Health Board, CMDHB is Counties Manukau District Health Board, WDHB is Waikato District Health Board and ChCh is Nurse Maude Association, Christchurch. ABI is ankle:brachial index.
Table 2. Compression use by study centre*
*Values are N (%). SD is standard deviation. ADHB is Auckland District Health Board, CMDHB is Counties Manukau District Health Board, WDHB is Waikato District Health Board and ChCh is Nurse Maude Association, Christchurch.
Pentoxifylline—Only one participant from Christchurch was receiving pentoxifylline at randomisation and no other participants were prescribed pentoxifylline during the 12-week follow-up.
Compression hosiery after healing—Overall 70% of the 90 participants who had healed at 12 weeks were using compression hosiery at 6 months after randomisation (Table 4). However, only 50% were wearing compression every day. There was considerable variation (17–50%) between the centres in the proportion of participants not wearing hosiery after healing.
Table 3. Dressings used by study centre*
* Values are N (%). Simple=non-adherent + absorbent; Moist = hydrogel + hydrocolloid + alginate + hydrofibre + foam; Medicated = silver-impregnated + iodophor. ADHB is Auckland District Health Board, CMDHB is Counties Manukau District Health Board, WDHB is Waikato District Health Board and ChCh is Nurse Maude Association, Christchurch.
Table 4. Use of compression hosiery after healing*
* Values in parentheses are percentages unless otherwise stated. SD is standard deviation. ADHB is Auckland District Health Board, CMDHB is Counties Manukau District Health Board, WDHB is Waikato District Health Board and ChCh is Nurse Maude Association, Christchurch. ABI is ankle:brachial index.
The four elements of a treatment regimen reported here are the first occasion that usual care of patients with venous leg ulcers in New Zealand has been compared to guideline recommendations in centres with organised services for leg ulcer management. As such, this study demonstrates that adherence to guideline recommendations can serve as quality measures that indicate opportunities for improvement.
Use of multilayer bandaging systems in the HALT trial was consistent with guideline recommendations, as were regional preferences for different bandaging systems. The preference for multilayer systems may reflect current knowledge as four layer elastic systems have been shown to deliver better healing rates than short stretch systems.11 However, there are two areas of incongruence with guideline recommendations, namely dressing selection and use of pentoxifylline. These inconsistencies offer clear opportunity for improvement and cost saving. Furthermore, although compression hosiery use after healing was generally congruent with guideline recommendations, compliance varied by region and may also represent an opportunity for improving outcomes.
There are no published New Zealand data specifically on the number of different types of dressings used in community-based management of venous ulcers. Internationally, audits reveal a variety of dressing products being used. A Swedish study found 51 dressings products being used in 294 patients,6 while an English study found 36 different dressings used in the treatment of patients with venous ulcers.7 With respect to dressings the central issue must be whether any dressing provides added benefit in terms of healing.
Three systematic reviews have found little evidence to support the view that any dressing, whether a simple dressing or a moist dressing, gives any benefit over compression alone.12–14 Moist wounds have been found to heal faster than dry wounds. 15 Moist wound dressings are designed to ensure that the wound surface is kept modestly moist, either through the donation of moisture in the case of hydrogels, the retention of moisture in the case of hydrocolloids, or through absorption of excess moisture in the case of alginates, hydrofibres and polyurethane foam dressings. However, venous ulcers under compression tend to be moist and a simple non-adherent dressing will prevent adhesion of bandages to the ulcer surface. Absorbent dressings may also be required on occasion to prevent maceration.
A recent addition to the range of available dressings is the silver impregnated dressing. Silver dressings in contact with wound fluid have antimicrobial activity against a variety of bacteria and fungi.16 However, these dressings tend to be the most expensive dressing option with the retail price for a 10 x 10 cm dressing being up to twice that of a similarly sized moist dressing and 19 times more expensive than a non-adherent dressing.
The most recent systematic review on this topic found a lack of evidence to support the routine use of silver dressings in ulcer care.17 Despite this finding, silver impregnated dressings are in regular use in New Zealand, accounting for 19% of the dressings used and 38% of the total spend on dressings in the HALT trial. The other group of medicated dressings are iodophor dressings, which contain cadexomer iodine and have antibacterial properties.18
A systematic review has found some evidence suggesting cadexomer iodine dressings may improve healing rates when used in conjunction with compression (RR 6.7, 95%CI 1.6 to 29.0), but the trials were small and of short duration (4 weeks).19 The implication of the review is that the evidence supporting the use of iodophor dressings is of limited reliability and such dressings should be used cautiously. Indeed, anything other than simple dressings should only be used when there is clear empirical need and all other evidence-based options have failed.
The New Zealand guideline recommendation for use of simple dressings needs to be considered in the light of the relative cost of such dressings. Although simple dressings accounted for about 29% of all usual care dressings in the HALT trial, expenditure on these dressings was 5% of the total spend. Using simple dressings, such as silicon-impregnated vicryl, presents a real opportunity for cost saving in the treatment of venous ulcers.
The almost complete absence of pentoxifylline as an adjuvant treatment among the participants in the HALT trial was a striking finding. The median period of ulcer duration prior to entry in the trial was 16 weeks, suggesting at least 50% of participants may have been candidates for treatment on the basis of the guideline recommendation.
Pentoxifylline has been shown to increase healing when used as an adjuvant to compression (RR 1.6, 95%CI 1.1 to 2.1) and to be the dominant economic strategy.20 Pentoxifylline appears to be particularly effective with slow to heal ulcers (RR 2.4, 95%CI 1.7 to 3.2),21 and such ulcers can be easily identified using a simple prognostic index. Thus candidate patients need not await treatment failure before being prescribed pentoxifylline. They can be prospectively identified using the Margolis index.22 Using this prognostic index, up to 97 (54%) participants in the usual care arm would have been candidates for treatment with pentoxifylline.
The main reasons for the low use of pentoxifylline are likely to be organisational and economic. Full subsidy of the drug was removed in 2003 and patients are now required to make a co-payment of approximately nine dollars per script. For a patient willing to pay, the district nurse needs to liaise with the general practitioner to make a case for prescription, the general practitioner has to apply to HealthPAC for special authority to prescribe and the drug has to be obtained from a hospital pharmacy in some areas, or approved retail pharmacy in other areas.
Another barrier to use is that the PHARMAC schedule only lists the drug as oxpentifylline. If the general practitioner searches for pentoxifylline, no hits are returned. Without amelioration of the above barriers, an opportunity to accelerate healing in a large group of patients may be missed.
There is an opportunity to improve on the use of compression hosiery and reduce ulcer recurrence. Thirty percent of the 90 participants in usual care who had healed at 12 weeks were not wearing any compression hosiery at six months. An additional 14% were not wearing compression hosiery every day. Ulcer recurrence can be more than halved over five years by use of compression hosiery after healing.23
The guidelines currently recommend class 3 hosiery as being more effective than class 2 hose, a recommendation based on 3-year follow up data from the only trial that has compared the two systems.24 A more recent publication of the five year follow up data from this trial found no significant difference between the two systems.25 It is probably preferable to recommend patients start on class 3 hose and drop down to a lower level of compression in order to maintain compliance than the reverse strategy, although any level of compression is preferable to none. Use of compression hosiery appears to be influenced by belief in the worth of the stockings,26 and practitioners may be able to influence this perception.
This secondary analysis of the HALT trial usual care arm is subject to limitations. The major limitation is that the trial participants may not reflect the typical experience of venous ulcer patients in New Zealand. It was not possible to determine how many patients were approached by district nurses to participate in the trial and thus how representative the sample may be. However, the HALT trial was a pragmatic trial with broad inclusion criteria and of the 392 potential participants notified to the researchers, 368 (94%) were randomised. There were no significant differences between participants registered and those randomised and it seems unlikely that patients outside of the HALT trial would have treatment regimens that more closely follow the New Zealand guidelines than those within the trial, especially in regions where there are no organised models of care for venous ulceration. Organised care has been shown to improve leg ulcer healing rates, better manage resource use and reduce costs compared to more naturalistically developed services.7 Therefore regions without organised models of care for venous ulcer management may be presented with greater opportunities to improve outcomes.
A lesser limitation of this study is that random variation may account for some of the regional differences observed, particularly where the numbers were small, such as with variation in the use of compression hosiery after healing.
Use of compression, both during an episode of venous ulceration and after healing, was generally consistent with recommendations in the New Guideline for Care of People with Chronic Leg Ulcers. However, simple dressings were used less frequently than more complex, expensive options and pentoxifylline was almost entirely absent from the armamentarium of care. Increasing use of simple dressings and prescribing pentoxifylline in appropriate patients represent opportunities for cost saving and improving rates of healing in patients with venous ulcers. Compliance with use of compression hosiery after healing may also benefit from attention.
Competing interests: None. (The study sponsors had no role in study design, data collection, analysis or interpretation, writing of the report, or in the decision to submit for publication. The corresponding author had full access to all data in the study and had final responsibility for the decision to submit for publication.)
Author information: Andrew Jull, Associate Professor at the School of Nursing and Senior Research Fellow at the Clinical Trials Research Unit, University of Auckland; Natalie Walker, Programme Director, Clinical Trials Research Unit, University of Auckland; Varsha Parag, Biostatistician, Clinical Trials Research Unit, University of Auckland; Anthony Rodgers, Professorial Fellow, George Institute for International Health, University of Sydney; Peter Molan, Professor of Biochemistry, University of Waikato and Director of the Waikato Honey Research Unit, Hamilton
Acknowledgements: The HALT trial was principally funded by a project grant from the Health Research Council of New Zealand. Comvita New Zealand Ltd provided an additional unconditional operational grant and supplied the manuka honey dressings. USL Medical Ltd provided the wound tracing grids.
This trial was designed and conducted with the support of the HALT collaborative group, consisting of the study authors, Professor Bruce Arroll (Department of General Practice and Primary Care, Auckland University, Auckland), Julie Betts (Waikato District Health Board, Hamilton), Cathy Hammond (Nurse Maude Association, Christchurch), Anita Latta (Auckland District Health Board, Auckland), Susan McAuley (Counties Manukau District Health Board, Otahuhu), and Dr Jill Waters (Auckland District Health Board, Auckland). The following people are thanked; the participants and their whānau; the trial research nurses: Sue Callender, Mary Cleland, Trish Johns, Anna Reid, Rachel White; Dr Young Mee Yoon (Comvita Ltd); Lucy Sanders (USL Medical Ltd).
Correspondence: Dr Andrew Jull, Associate Professor, School of Nursing, University of Auckland, Private Bag 92019, Auckland Mail Centre, New Zealand. Fax: +64 (0)9 367-7158; email: firstname.lastname@example.org
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