TITLE: Australian Sheepskins for the Management of Pressure Ulcers: A Review of the Clinical-Effectiveness, Cost-Effectiveness, and Guidelines DATE: 21 July 2009 CONTEXT AND POLICY ISSUES: Pressure ulcers, also known as decubitus ulcers, are areas of ulceration and necrosis where tissues are compressed between bony prominences and surfaces. 1 Common points of ulcer development are at the base of the spine, hips, elbows, and heels 2 and are the result of pressure alone or pressure combined with friction and or shearing forces. 1 Pressure ulcers can range in severity from early-stage ulcers to late-stage ulcers. 1 Risk factors for pressure ulcers include, old age, impaired circulation, immobilization, malnourishment, and incontinence. 1 The highest incidence of pressure ulcers occurs in older patients in long-term care facilities or hospitals. 1 The prevalence of pressure ulcers in Canada ranges between approximately 5.0% in the hospital setting and up to 30% for spinal cord injured patients in the community. 2 In the United Kingdom, it has been estimated that it costs between 600,000 and 3,000,000 to prevent and manage pressure ulcers in a large general hospital (600 beds). 2 Common actions to prevent and or manage pressure ulcers include: relieving pressure, caring directly for the ulcer, managing pain, managing infection, managing malnutrition, adjunctive therapy (e.g., negative pressure therapy), and or surgery. 1 To relieve pressure through support surfaces, the device is placed under or around the patient s body to disperse pressure over a larger surface area. 2,3 Examples of pressure relieving surfaces are specialized mattresses (e.g., fibre-filled, gel-filled, air-filled) and overlays (e.g., sheepskin, gel-filled, water-filed, bead-filled). The costs of these pressure relieving devices varies substantially, with one review citing prices ranging between 100 to 30,000. 2 Disclaimer: The Health Technology Inquiry Service (HTIS) is an information service for those involved in planning and providing health care in Canada. HTIS responses are based on a limited literature search and are not comprehensive, systematic reviews. The intent is to provide a list of sources and a summary of the best evidence on the topic that CADTH could identify using all reasonable efforts within the time allowed. HTIS responses should be considered along with other types of information and health care considerations. The information included in this response is not intended to replace professional medical advice, nor should it be construed as a recommendation for or against the use of a particular health technology. Readers are also cautioned that a lack of good quality evidence does not necessarily mean a lack of effectiveness particularly in the case of new and emerging health technologies, for which little information can be found, but which may in future prove to be effective. While CADTH has taken care in the preparation of the report to ensure that its contents are accurate, complete and up to date, CADTH does not make any guarantee to that effect. CADTH is not liable for any loss or damages resulting from use of the information in the report. Copyright: This report contains CADTH copyright material. It may be copied and used for non-commercial purposes, provided that attribution is given to CADTH. Links: This report may contain links to other information available on the websites of third parties on the Internet. CADTH does not have control over the content of such sites. Use of third party sites is governed by the owners own terms and conditions.
One type of protective padding used to relieve pressure is sheepskin which is added in layers to chairs or beds with the intent of restoring adequate blood flow to the areas vulnerable to pressure ulcer development. 4 Sheepskin has been used for both prevention and management of pressure ulcers. 1 This review is required to help determine whether the use of Australian sheepskin for preventing and managing pressure ulcers is a clinically-effective and costeffective measure. RESEARCH QUESTIONS: 1. What is the clinical-effectiveness of Australian sheepskins for the management of pressure ulcers? 2. What is the cost-effectiveness of Australian sheepskins for the management of pressure ulcers? 3. What are the guidelines for use of Australian sheepskins for the prevention and management of pressure ulcers in elderly bedridden patients? METHODS: A limited literature search was conducted on key health technology assessment (HTA) resources, including PubMed, the Cochrane Library (Issue 2, 2009), University of York Centre for Reviews and Dissemination (CRD) databases, ECRI, EuroScan, international health technology agencies, and a focused Internet search. The search was limited to English language articles published between 2004 and June 2009. No filters were applied to limit the retrieval by study type. Internet links were provided, where available. HTIS reports are organized so that the higher quality evidence is presented first. Therefore, HTA reports, systematic reviews, and meta-analyses are presented first. These are followed by randomized controlled trials (RCTs), controlled clinical trials, observational studies, economic evaluations, and evidence-based guidelines. Additional information that may be of interest can be found in Appendix 1. SUMMARY OF FINDINGS: Three relevant systematic reviews 2,5,6 and two guidelines 3,7 were identified. The systematic reviews focused on the prevention of pressure ulcers and the guidelines focused on the management of pressure ulcers. One relevant RCT was retrieved. However, it was included in at least one systematic review presented in the HTIS report and is therefore not summarized. No relevant HTAs, observational studies, or economic studies were identified. All three of the systematic reviews 2,5,6 concluded that medical sheepskins were superior to standard treatment when evaluating the incidence of pressure ulcers for patients in the hospital or rehabilitation ward. The included studies were similar for each of the systematic reviews. The systematic review authors were inconsistent in reporting whether the medical sheepskin used was Australian. However, one review 2 specifically mentioned that the results apply to Australian medical sheepskin. Thus, given the similar, if not identical, literature base, it can be reasonably assumed to apply to the remaining systematic reviews as well. Two evidence-based guidelines that specifically mentioned medical sheepskins were retrieved. 3,7 One reported that there was no evidence to recommend sheepskin for managing Australian Sheepskin for the Management of Pressure Ulcers 2
ulcers and the other guideline was a from a health insurance agency that recommended coverage of sheepskin overlays for treatment of existing ulcers if specific medical criteria were met. Systematic reviews and meta-analyses In a published update of a Cochrane systematic review on the use of support surfaces for the prevention of pressure ulcers, McInnes et al. (2008) concluded that medical grade sheepskins are correlated with a decrease in incidence of pressure ulcers. 2 In this study, the authors investigated the clinical-effectiveness of constant or continuous low pressure devices (CLP), including sheepskin. The primary outcomes of interest were the occurrence and severity of new pressure ulcers. The literature was searched up to February 2008 and included relevant RCTs. Of the 52 RCTs included for review, three focused on the use of sheepskin and pressure ulcer occurrence. The first RCT was a study from 1964 and did not find any difference in the incidence of pressure ulcers when sheepskins were added to standard hospital mattresses compared to standard hospital mattresses without an overlay. The type of sheepskin used was not reported. McInnes et al. reported that this trial was underpowered (i.e., too small of a sample size) to detect a difference; sample size was not reported. The patients were elderly (mean age=72.5 yrs), confined to bed, and were in the geriatric unit of a convalescent hospital. Methodology was reported to be poor and it was reported that allocation concealment was unclear. Other methodological details such as whether the outcome assessor was blinded were not reported. The follow-up period was six months. The results of the other two trials were pooled (n=738) and 40% of the patients were from the second trial comprised of elderly (aged 60 years and over) orthopedic patients transferred to a rehabilitation ward. The remaining 60% were from the third trial and were a mixed inpatient adult population. The patients from both trials were at low to moderate risk of developing pressure ulcers. Both trials compared Australian medical sheepskin to standard treatment and both trials measured the incidence of pressure ulcers. Standard treatment for the orthopedic patients was a standard hospital mattress and other low technology CLP devices, as required. For the mixed inpatient trial, standard treatment included patient repositioning and pressure relieving devices with or without CLP. The follow-up period was unclear for one trial and not reported for the second trial. The pooled estimate was statistically significantly in favour of the Australian medical sheepskin [risk ratio 0.42, 95% CI: 0.22 to 0.81]. The meta-analysis was performed with a random-effects model and heterogeneity as measured by I 2 was 67%. Allocation concealment was adequate for the trial assessing the mixed inpatient population but was not adequate for the RCT with the orthopedic population. Study selection, data extraction, and assessment of included study quality for the systematic review were performed by at least two researchers and more than two databases were searched. Grey literature (literature not commercially published) searching appeared to be limited to the Cochrane Wounds Group Specialised Register which may have resulted in missed relevant literature from other sources such as health technology agencies. The allocation concealment was known for the three trials (one adequate) but other methodological qualities of the trials were not reported. Thus, it is not known how the methodology could have affected the results of the pooled estimate, and it is therefore unclear whether the conclusions of the authors were based on rigorous and well designed trials. Heterogeneity and the differences between the patient populations were not discussed by McInnes et al. Australian Sheepskin for the Management of Pressure Ulcers 3
Two additional systematic reviews were retrieved, one by Cullum et al. 5 (2008) and one by Reddyet al. 6 (2006). Both sets of authors concluded that medical sheepskin overlays reduced the incidence of pressure ulcers when compared to standard hospital mattresses 6 or compared to standard care. 5 The studies included in both of these systematic reviews were the same studies included in the McInnes et al. 2 and are therefore not summarized in detail here. Guidelines and recommendations In 2005, the Royal College of Nursing published a clinical practice guideline on The management of pressure ulcers in primary and secondary care. 7 Part of the guideline assessed the value of CLP devices. No recommendation specific to sheepskin was reported. Studies had to be RCTs and patients had to have pressure ulcers to be included as evidence for the use of CLP devices for managing pressure ulcers. There were no patient setting restrictions. Examples of included CLP devices are sheepskin, air flotation beds, and gel-filled mattresses or overlays. The authors of the guideline found one RCT published in 1964 that compared sheepskin overlays on hospital mattresses to no sheepskin overlays on hospital mattresses. The authors for this guideline stated that the outcome for this trial was reduction of red skin around the ulcer, the results were inconclusive, and the methodology was poor. This was the same RCT that was included in the McInnes et al. 2 and Reddy et al. 6 systematic reviews. The methods used to develop the guideline were consistent with National Institute for Health and Clinical Excellence (NICE) methods for guideline development which included a systematic literature review, article selection (two reviewers), and data extraction, summarizing the literature, generating a consensus statements for areas lacking sufficient evidence, formulating and grading the recommendations, submitting guidelines to NICE stakeholders organizations for comment and consider comments, and lastly submitting the guidelines to NICE. The guidelines were peer-reviewed. Aetna, an American health insurance company, published a clinical policy bulletin on pressure reducing support surfaces. 3 The latest review of the policy was June, 2009. Sheepskin and lambswool pads were covered under the policy for patients who met the following specific medical criteria: Patient has multiple ulcers on trunk or pelvis with partial thickness skin loss involving epidermis and or dermis; patient has had comprehensive ulcer treatment for at least a month including the use of mattress overlay; patient s ulcers have worsened or not improved over the past month; or Patient has large or several pressure ulcers on trunk or pelvis that have full thickness tissue loss or deep tissue destruction that may extend down to but not through underlying fascia; or Patient has had a myocutaneous flap or skin graft for the pressure ulcer on the trunk or pelvis and surgery in the past 60 days for this condition and has been using the alternative pressure, low air mattresses, or overlays in the past 30 days since discharge from hospital or nursing facility. If these criteria are not met, the treatment is considered experimental. Australian Sheepskin for the Management of Pressure Ulcers 4
The clinical policy guidelines do not contain a methodology section, thus the evidence base of the policy is unclear. In addition, the recommendations are not graded. Aetna does report that it s Clinical policy bulletins are based on peer-reviewed evidence, technology assessments, structured evidence reviews, evidence-based consensus statements, evidence-based guidelines from nationally recognized professional healthcare organizations and public health organizations, and expert opinions. 8 Aetna did not specifically mention Australian sheepskin in their policy. Limitations Non-English language, non-published, or non peer-reviewed articles were not included in this report. In addition, articles had to be published within the last five years to be included. These literature parameters may have impacted the general literature review as well as the conclusions of this report. One of the two RCTs that reported statistical significance included in the systematic reviews 2,5,6 was not of high methodological quality based on reporting of allocation generation, allocation concealment, blinding of outcome assessor, intent-to-treat analysis, and follow-up periods. The second RCT was of higher quality based on allocation generation and concealment as well as stated follow-up schedules for each group. The third RCT did not report statistical analyses and also was of poor methodological quality as it was underpowered and it was unclear whether there was allocation concealment. The patient population of the three RCTs in the systematic reviews was limited to elderly patients in rehabilitation ward, mixed adult inpatients in a hospital, and elderly patients in a convalescence hospital. Other patient subpopulations would be of interest, for example patients in nursing homes. In addition, all patients were at risk of developing ulcers. Thus, no trials focused on using medical sheepskin to manage existing ulcers. One RCT provided follow-up details and reported the length was eight days. This may not have been a sufficient duration to assess effectiveness for patients in long-term care. Another trial had a six month follow-up period but the overall design was poor and the sample size was 36 patients which may have been too small to detect differences. Large, well-designed RCTs with adequate follow-up times are lacking. Many guidelines were identified in the literature search that focused on pressure ulcers, however, only two mentioned the use of sheepskin. 3,7 One guideline 7 did not have a recommendation for or against sheepskin. The evidence base was one, underpowered study from 1964 and did not consider the two more recent RCTs that determined Australian medical sheepskin was clinically-effective. Thus, the guideline can be considered outdated. It was unclear what evidence-base was used for the second guideline. 3 No full economic evaluations that assessed the cost-effectiveness of Australian sheepskins for preventing or managing pressure ulcers were identified. Relevant partial economic evaluations were also not identified. CONCLUSIONS AND IMPLICATIONS FOR DECISION OR POLICY MAKING: For the question related to the use of Australian medical sheepskins for the prevention of pressure ulcers, three systematic reviews 2,5,6 were identified. These systematic reviews all concluded that medical sheepskin was more effective than standard care, all based their Australian Sheepskin for the Management of Pressure Ulcers 5
conclusions on the same two or three RCTs, and all mentioned the lack of methodologically rigorous trials. No guidelines on the use of medical sheepskins for the prevention of pressure ulcers were identified. No clinical trials regarding the use of medical sheepskin for the management of existing pressure ulcers were identified. Two guidelines 3,7 about management of existing pressure ulcers were retrieved with conflicting opinions. One large insurance company indicated that sheepskin would be a covered medical expense if the patient met specific criteria. 3 The methods used and evidence identified were unknown. The second guideline 7 indicated that sheepskin as a standard care was not effective. However, the authors of this guideline did not consider the more recent RCTs that found medical sheepskin to be statistically more effective than standard care in reducing the incidence of pressure ulcers. Well-designed, multi-centered RCTs that enroll various patient populations are needed before the clinical-effectiveness can be firmly established. Furthermore, without cost information, it is difficult to know whether Australian sheepskins are cost-effective when compared other treatments for prevention of pressure ulcers. The decision to purchase Australian medical sheepskins for the prevention of pressure ulcers can be done with some supporting clinical evidence and no economic information. The lack of clinical guidelines makes it difficult to determine when and how to use medical sheepskins. The decision to purchase Australian medical sheepskins for the management of existing ulcers cannot be supported with consistent, clear clinical evidence or any economic evidence. This lack of economic information and the lack of guidelines should be considered when making decisions about the use of Australian sheepskin. PREPARED BY: Rhonda Boudreau, MA, BEd, BA (Hons), Research Officer Emmanuel Nkansah, BEng, MLS, MA, Information Specialist Health Technology Inquiry Service Email: htis@cadth.ca Tel: 1-866-898-8439 Australian Sheepskin for the Management of Pressure Ulcers 6
REFERENCES: 1. Merck. Pressure ulcers. In: Merck manual professional[database online]. Whitehouse Station(NJ): Merck; 2008. Available: http://www.merck.com/mmpe/sec10/ch126/ch126a.html (accessed 2009 Jun 26). 2. McInnes E, Bell-Syer SE, Dumville JC, Legood R, Cullum NA. Support surfaces for pressure ulcer prevention. Cochrane Database Syst Rev 2008;(4):CD001735, 2008. Available:http://mrw.interscience.wiley.com/cochrane/clsysrev/articles/CD001735/frame. html (accessed 2009 Jul 20). 3. Aetna. Pressure reducing support surfaces. In: Clinical policy bulletin [database online]. Hartford(CT): Aetna; 2009. Number 0430. Available: http://www.aetna.com/cpb/medical/data/400_499/0430.html (accessed 2009 Jun 26). 4. Erstad S. Pressure sores:home treatment. Vancouver: HealthLink BC; 2007. Available: http://www.healthlinkbc.ca/kbase/topic/mini/tp17772/hometrt.htm (accessed 2009 Jun 26). 5. Cullum NA, Petherick E. Pressure ulcers. Clin Evid (Online) 2008;2008, 2008. 6. Reddy M, Gill SS, Rochon PA. Preventing pressure ulcers: a systematic review. JAMA 2006;296(8):974-84. 7. Royal College of Nursing (RCN). The management of pressure ulcers in primary and secondary care: a clinical practice guideline. London: NICE; 2005. Available: http://www.nice.org.uk/nicemedia/pdf/cg029fullguideline.pdf (accessed 2009 Jun 26). 8. Clinical Policy Bulletins (CPBs). Hartford (CT): Aetna, Inc; 2009. Available: http://www.aetna.com/cpb/cpb_menu.html (accessed 2009 Jul 8). Australian Sheepskin for the Management of Pressure Ulcers 7
APPENDIX 1: Additional Information Protocol for Systematic Review The objectives of the following Cochrane systematic review are to determine whether support surfaces and pressure relieving devices (such as beds, mattress overlays, mattress replacements and heel splints) prevent pressure ulcers on the heels of patients in all care settings. As there is no abstract, no further information is available. This systematic review is in its protocol phase and is thus not yet complete. Donnelly J, Kernohan GW, Witherow A. Pressure relieving devices for preventing heel pressure ulcers. Donnelly Jeannie, Kernohan George W, Witherow Anne Pressure relieving devices for preventing heel pressure ulcers Cochrane Database of Systematic Reviews: Protocols 2008 Issue 2 John Wiley & Sons, Ltd Chichester, UK DOI: 10 1002/14651858 CD007117 2008;(2). Cochrane ID: CD007117 Available: http://www.mrw.interscience.wiley.com/cochrane/clsysrev/articles/cd007117/frame.html (accessed 2009 Jul 20). This is the protocol for a review and there is no abstract. The objectives are as follows: To determine whether support surfaces and pressure relieving devices (such as beds, mattress overlays, mattress replacements and heel splints) prevent pressure ulcers on the heels of patients in all care settings Protocol for RCT Mistiaen et al. published the protocol of a multi-centre RCT on the cost-effectiveness of Australian sheepskin for prevention of ulcers in nursing homes. The authors aim to compare the use of Australian sheepskin in addition to usual care compared to usual care only for preventing the occurrence of sacral pressure ulcers. This study is registered with Cochrane Library: The Netherlands Organisation for Health Research and Development (ZonMw). Costeffectiveness of the Australian medical sheepskin for the prevention of pressure ulcers in somatic nursing home clients (project) (Project record). The Netherlands Organisation for Health Research and Development (ZonMw) 2006; Cochrane ID: HTA-32006001362 Notes: Record Available: http://www.mrw.interscience.wiley.com/cochrane/clhta/articles/hta- 32006001362/frame.html (accessed 2009 Jul 20). Australian Sheepskin for the Management of Pressure Ulcers 8