A systematic review of economic evaluations assessing interventions aimed at preventing or treating pressure ulcers.

International Journal of Nursing Studies 52 (2015) 769–788

Contents lists available at ScienceDirect

International Journal of Nursing Studies journal homepage: www.elsevier.com/ijns

Review

A systematic review of economic evaluations assessing interventions aimed at preventing or treating pressure ulcers Simon J. Palfreymana,*, Patricia W. Stoneb a b

Sheffield Teaching Hospitals NHS Foundation Trust, Sheffield University, Sheffield, UK School of Nursing, Columbia University, New York, USA

A R T I C L E I N F O

A B S T R A C T

Article history: Received 25 July 2013 Received in revised form 10 June 2014 Accepted 12 June 2014

Background: Pressure ulcers have an adverse impact on patients and can also result in additional costs and workload for healthcare providers. Interventions to prevent pressure ulcers are focused on identifying at risk patients and using systems such as mattresses and turning to relieve pressure. Treatments for pressure ulcers are directed towards promoting wound healing and symptom relief. Both prevention and treatments have associated costs for healthcare providers. The aim of this study was to systematically review the economic evidence for prevention and treatment interventions for pressure ulcers. Design: A systematic review of comparative clinical studies that evaluate interventions to either prevent or treat pressure ulcers. Data sources: Searches of the major electronic databases were conducted to identify citations that reported costs or economic analysis for interventions directed towards prevention or treatment of pressure ulcers. Only comparative clinical studies were included. Review articles, case-series, non-randomised studies, and studies in a foreign language that did not have an abstract in English were excluded from the review. Review methods: Decisions regarding inclusion or exclusion were based on a consensus of the authors after review of the title or abstract. Potential citations were obtained for more detailed review and assessed against the inclusion criteria. The studies identified for inclusion were assessed against the 24 key criteria contained in the CHEERS checklist. Costs were standardised to US dollars and adjusted for inflation to 2012 rates. Results: The searches identified 105 potential studies. After review of the citations a total of 23 studies were included: 12 examined prevention interventions and 11 treatments. Review against the CHEERS criteria showed that the majority of included trials had poor reporting and a lack of detail regarding how costs were calculated. Few studies reported more than aggregate costs of treatments with only a small number reporting unit cost outcomes. Conclusions: Existing evidence was poor in regard to the economic evaluation of interventions for the prevention and treatment of pressure ulcers. Much of the published literature had poor reporting quality when compared to guidelines which provide key criteria for studies to adequately examine costs within an economic analysis. ß 2014 Elsevier Ltd. All rights reserved.

Keywords: Economic evaluations Pressure ulceration Wound care Systematic review

* Corresponding author. Tel.: +44 114 2222991. E-mail address: s.palfreyman@sheffield.ac.uk (P. Simon J.). http://dx.doi.org/10.1016/j.ijnurstu.2014.06.004 0020-7489/ß 2014 Elsevier Ltd. All rights reserved.

770

P. Simon J., S. Patricia W. / International Journal of Nursing Studies 52 (2015) 769–788

What is already known about the topic? Pressure ulcers are costly in terms of their impact on resources and patient morbidity. There are a number of different products and strategies available for the prevention and treatment of pressure ulcers. Economic analyses help funders in their decisions between alternate interventions. Best practice checklists and consensus statements are available for economic analyses. What this paper adds The paper is currently the only study that has evaluated the published studies describing interventions for the prevention and treatment of pressure ulcers. Prevention strategies are a more cost-effective strategy than treatment of pressure ulcers. The current economic evidence for pressure ulcers is poorly reported. 1. Background Pressure ulcers are a ‘‘localised injury to the skin and/or underlying tissue usually over a bony prominence, as a result of pressure, or pressure in combination with shear’’ (National Pressure Ulcer Advisory Panel and European Pressure Ulcers Advisory Panel, 2009). They are graded based on the depth and damage to the skin and surrounding tissues (Beeckman et al., 2007). This grading also influences the treatment choices and actions required of clinicians. One illustration of this is the requirement by the UK Department of Health, via the National Patient Safety Agency, that all ulcers Grade 3 and over must be fully investigated and their causal factors determined (National Patient Safety Agency, 2011). Pressure ulcers impact patients, families and clinicians in many different ways. They impact patients by reducing their quality and length of life. They also cause distress to their relatives and caregivers (Moore and Cowman, 2009; Sorenson and Lyons, 2009). Pressure ulcers affect clinical staff in terms of increased workload linked to documentation, treatment, prevention and collection of data. Pressure ulcers are associated with increased costs and resource use, which impact healthcare systems (Bennett et al., 2004; Brem et al., 2010; Stinson et al., 2013). Finally, they are also being considered as a proxy by regulators as an overall indicator of quality of care (Mueller and Karon, 2004). 2. Prevention and treatment of pressure ulcers The primary focus of interventions related to pressure ulcers should be towards prevention as this is less costly for healthcare providers and less traumatic for the patient (Reddy et al., 2006). The principle aim of interventions to prevent pressure ulcers are focussed on identifying patients at risk of ulceration, reducing pressure and minimising shear and friction that contribute to pressure ulcer development (Reddy et al., 2006). The main assessment tools used within the UK, Europe and North America

are the Braden (Braden and Bergstrom, 1994) and Waterlow scales (Waterlow, 1991). These tools are based on scoring algorithms of factors associated with pressure ulcers development and seek to identify those patients at high risk of pressure ulcer development. Interventions to relieve pressure and prevent ulcers can then be applied. Common prevention interventions include turning regimes, pressure relieving beds and mattresses, as well as off-loaders for heels. Unfortunately, the evidence to support the majority of these interventions has been referred to as equivocal at best, and absent at worst, with few high quality comparative effectiveness studies (Reddy et al., 2006). Some of the interventions such as two hourly turns are based on tradition rather than empirical evidence (Defloor et al., 2005) and the pressure relieving equipment may not have been evaluated in terms of their costs and benefits. Once a pressure ulcer has occurred the main treatments are focussed towards promoting wound healing through the application of various types of wound dressings. Such dressings may also help with wound debridement, reduce bacterial load and prevent further trauma. However, unless the underlying causes and risk factors (i.e. pressure, shear and friction) are addressed, the treatments are likely to be ineffective. Systematic reviews have criticised the evidence for the effectiveness of such dressings for pressure ulcers as being of poor quality (Bouza et al., 2005). One important consideration for healthcare providers has been the impact that pressure ulcers have on the cost of health care. One study, frequently quoted in the UK, was conducted by Bennett et al. in 2004 and estimated that the cost of pressure ulceration was up to 4% of UK NHS expenditure and was between £1.4 and £2.1 billion per year. It was also estimated that an average district general hospital in the UK spent anywhere between £600,000 and £3 million on treating pressure ulcers each year; however, this estimate is 20 years old (Touche Ross, 1994). More recently, researchers found the cost per admission for hospital acquired grade 4 pressure ulcers to be on average $129,248 USD (Brem et al., 2010). In all these estimates, the main cost driver is the amount of nursing time involved in the care of this group of patients related to treatment of complications such as wound infection. Therefore, understanding the attributable costs of prevention and treatment of pressure ulcers may help in the implementation of effective strategies in clinical practice. Economic analyses have become increasingly important as a basis for deciding between treatments and interventions. Economic analyses are concerned with evaluating the consequences of alternative interventions in order to make choices in a world with limited resources (Frick et al., 2013; Freund and Dittus, 1992). There are four different types of economic analyses: costminimisation, cost-effectiveness, cost-utility and cost– benefit. Cost-minimisation is an appropriate analysis when the outcomes for the interventions being compared are the same and is used to identify the least costly alternative (Briggs and O’Brien, 2001). Cost-effectiveness studies measure cost on the basis of a single consequence in terms of cost per unit. For example, cost per pressure ulcer prevented or cost per life year gained. Costeffectiveness analyses results are usually expressed in


terms of an incremental cost-effectiveness ratio, which is the additional cost incurred for each extra unit compared to the next most effective alternative (Drummond et al., 2005; Detsky and Naglie, 1990). Cost-utility analyses specific type of cost-effectiveness analysis in which the outcome is measured in terms of quality adjusted life years, which is a patient preference based outcome. Cost–benefit analysis is only concerned with the cost in term of monetary impact. The classic book by Drummond et al. provides additional details of the different forms of economic analysis in health care (Drummond et al., 2005). Additionally, further explanations of these analyses with nursing examples are available in a chapter written by Frick et al. (2013). In assessing the quality of economic evaluations there have been checklists in the literature for over a decade, which were based on recommendations made by a national panel of experts in the United States and the UK (Drummond and Jefferson, 1996; Evers et al., 2005; Stone, 1998; Stone et al., 2002). Recently, the Consolidated Health Economic Evaluation Reporting Standards (CHEERS) checklist was published, which has been supported by the International Society for Pharmacoeconomics and Outcomes Research (ISPOR) organisation (Husereau et al., 2013); and this new 24-item checklist has been jointly endorsed by BMJ and nine other publications. All of the checklists have a number of key criteria in common that need to be reported in order for studies to adequately examine costs within an economic analysis. The CHEERS checklist includes 10 basic areas: (1) title and abstract (2 items); (2) introduction (1-item); (3) methods (14 items); (4) results (4-items); (5) discussion (1item); and (6) other, which is related to funding and conflict of interest (2-items). Not all questions can be applied to all studies as the checklist covers questions related to costeffectiveness modelling and preference-based outcomes, which are not appropriate to all methods (e.g., only cost utility analyses have preference-based outcomes). However, it does specify clear criteria that studies that purport to be economic analyses should include. Such checklists can give an indication of how well the published literature are adhering to the established guidelines and criteria for the reporting of economic analyses. A limitation to any such checklist is that is simply gives an indication of how many items have been included or excluded within an article but not the relative importance. However, it can be inferred that those articles who answer and include more criteria from the checklists are likely to be of higher quality. 3. Aims and objectives The aim of this study was to systematically review economic evidence on the costs of interventions designed to prevent and/or treat of pressure ulcers. The recent publication of the CHEERS checklist also offered an opportunity to examine how well the published literature reported the recommended key criteria that had been identified for reporting economic analyses. 4. Methods A systematic review was conducted to identify studies that evaluated interventions to either prevent or treat

771

pressure ulceration. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines (Moher et al., 2009) were followed in this report. Studies were included if they were comparative clinical studies (i.e. those had more than one intervention or treatment), evaluated interventions to either treat or prevent pressure ulcers and reported cost data as an outcome. The search was restricted to those studies published after 1990 as it was around this time that advanced wound dressings and pressure relieving equipment were becoming established (Bouza et al., 2005). Searches were conducted of the major electronic databases including: Medline, CINHAL, Cochrane Library, EconLit, NHS Economic Evaluations database, and Science Citation index. The text word and MeSH headings used in the search are shown in Table 1 and the search strategy in Table 2. Specific types of literature and studies were excluded: review articles, case-series, non-randomised studies, and studies in a foreign language that did not have an abstract in English. The search strategy was conducted by the primary author (SP) and reviewed by a librarian. The inclusion strategy inherently favours studies conducted/ written by English speaking investigators, thus favouring English speaking countries. Also, there was no attempt to include grey literature, which may result in a publication bias. Searches of the databases were conducted to identify suitable studies. The results of the searches were initially screened on the basis of the title and the abstract. Those studies that clearly did not evaluate interventions to prevent or treat pressure ulcers and did not report costs were excluded. Full text articles were obtained and further evaluation regarding their suitability assessed. Decisions regarding inclusion or exclusion were based on a consensus of both authors after review of the title or abstract. Potential citations were obtained for more detailed review and assessed against the inclusion criteria. The studies identified for inclusion were assessed against the 24 key criteria identified in the CHEERS checklist (Husereau et al., 2013) and a score was given based on the total number of applicable items in each study. Additional data were extracted on the type of study, costs reported, country of origin, grading and assessment of pressure ulcers, methods of economic analysis, and type of economic modelling. All abstracted data were audited by the primary author (SP) and reviewed by the senior author (PS). The costs identified within the studies were standardised into US dollars based on the yearly mean historic exchange rate (http://www.ukforex.co.uk/forex-tools/historical-rate-tools/yearly-average-rates) and the costs were adjusted for inflation to 2012 using the US Department of Labour Consumer Price Index figures (http://www.bls.gov/ data/inflation_calculator.htm). If the year was not stated then costs were adjusted to two years prior to the publication date. 2012 US dollar amounts were then computed into 2012 Euros using the average annual exchange rate of s0.872–$1 obtained from the US Internal Revenue Service website (http://www.irs.gov/Individuals/


772 Table 1 Details of search strategy. Search criteria

Electronic databases Keywords/synonyms

Population

Adult patients with a Grade 2 or greater pressure ulcer Adult patients at risk of developing a Grade 2 or greater pressure ulcer

Pressure ulcer Pressure sore Decubitus ulcer Bed sore

Intervention

Treatments to heal pressure ulcers. Treatments to reduce the risk of developing a pressure ulcer

Wound dressing Bed Mattress Boot Pressure relief Pressure reduction Prevention

Comparison

Outcomes

Healing rate Cost Quality of life

Randomised controlled trial Clinical trial Economic evaluation Systematic review Cost-effective Cost-benefit Cost-utility Wound healing Cost Economic evaluation Quality of life HRQoL

International-Taxpayers/Yearly-Average-Currency-Exchange-Rates). All cost data are reported in 2012 US dollars and 2012 Euros. Data were entered into an Excel spreadsheet and analysed using SPSS version 20. Table 2 Search strategy. Searches 1 2 3

4 5 6 7

8 9 10 11 12 13 14 15 16 17 18 19

Results pressure ulcer.tw. or exp Pressure Ulcer/ Pressure sore.tw. bed sore.mp. (mp = title, abstract, original title, name of substance word, subject heading word, keyword heading word, protocol supplementary concept, rare disease supplementary concept, unique identifier) decubitus ulcer.tw. 1 or 2 or 3 or 4 clinical trial.tw. or exp Clinical Trial/ exp Randomised Controlled Trials as Topic/or randomised controlled trial.tw. or exp Clinical Trials as Topic/ comparative trial.tw. 6 or 7 or 8 5 and 9 exp Economics/or exp Cost-Benefit Analysis/or economic analysis.tw. or exp ‘‘Costs and Cost Analysis’’/ economic evaluation.tw. quality of life.tw. cost-effectiveness.tw. cost-utility.tw. or exp Quality-Adjusted Life Years/ cost-minimisation.tw. cost-minimisation.tw. 11 or 12 or 13 or 14 or 15 or 16 or 17 10 and 18

Medline CINAHL Cochrane Controlled Trials Register Cochrane Database of Systematic Reviews EMBASE EconLit NHS Economic Evaluations Database PubMed (last 180 days) Science Citation Index (no restrictions)

5. Results The initial searches identified a total of 186 citations: 120 Medline, 25 CINHAL, 19 Science Citation Index, 21 Cochrane Library, 1 EconLit and 0 NHS Economic Evaluations database. After deletion of duplicates and those which were clearly outside the subject area, a total of 103 potential studies were identified for inclusion. On initial examination based on review of the abstracts: a further three studies were found to be duplicates, 29 studies were excluded as they were review articles, provided no cost data or evaluated other wound types (e.g. moisture lesions, venous ulcers or diabetic wounds). This left a total of 74 citations that were included for full-text review: thirty-five of the studies evaluated interventions to prevent pressure ulcers and 39 citations were interventions to treat pressure ulcers. On appraisal of the 35 prevention studies, the majority of these provided no cost data or inadequate cost data (n = 16), two were reviews, three were duplicate publications, one compared purchasing strategies and one had no English translation, which provided sufficient detail for data extraction. Therefore, a total of 12 studies evaluating interventions to prevent of pressure ulcers were included in the review. Of the 39 potential studies that evaluated treatments for pressure ulcers many (n = 18) were excluded as they did not report cost data, five were found to be review articles, and five had no English translations which provided sufficient detail for data extraction. A total of

P. Simon J., S. Patricia W. / International Journal of Nursing Studies 52 (2015) 769–788 Table 3 Description of included studies. Country of study Prevention (n = 12)

Treatment (n = 11)

US Canada

2 4

US Canada

6 1

UK Europe Other

3 2 1

UK Europe Other

0 2 2

Prevention

Treatment 3 3 6

Government Industry Not stated

0 7 4

Interventions Mattress Off-loading device Multi-faceted Dressing Chemical

7 1 2 1 1

Wound dressing Mattress Electrical stimulation

8 2 1

Perspective Health care Unclear or not stated 3rd party payer

8 3 1

Health care Unclear or not stated

10 1

Identification

Source of funding Government Industry Not stated

Records idenfied through database searching (n = 186 )

773

11 studies evaluating treatments were therefore included in the review. Table 3 shows details of the included studies. A detailed breakdown of the screening of the articles is shown in the PRISMA flowchart (Fig. 1). The Appendix has evidence tables for the 12 prevention and 11 treatment studies included showing descriptions of the studies in terms of year of publication, study type, country, time horizon and major findings as well as tables of the CHEERS checklist abstracted data. 5.1. Findings of the prevention studies 5.1.1. Mattresses and support surfaces The majority of the included studies (n = 8) evaluated the impact of mattress products for the prevention of pressure ulcers. The studies were conducted in a variety of settings: three studies (Gebhardt et al., 1996; Inman et al., 1993, 1999) were conducted in Intensive Care Units (ICUs); one in spinal injury centre (Catz et al., 2005); one in an orthopaedic unit (Price et al., 1999); one in the operating theatre (Pham et al., 2011b); one in long term care (Pham et al., 2011a); and, one included vascular, orthopaedic and medical elderly units (Iglesias et al.,

Addional records idenfied through other sources (n =4 )

Screening

Records aer duplicates removed (n = 103 )

Records screened (n = 103 )

Excluded based on abstract

Included

Eligibility

Review arcles n= 15 No cost data reported n= 5 Other wound types n= 9 Full-text arcles assessed for eligibility (n = 74 )

Studies included in qualitave synthesis (n =23 )

Full-text arcles excluded, with reasons (n = 51 ) No cost data reported n= 34 Review arcles n= 7 No English translaon n= 6 Addional duplicates n=3 Other n=1

Fig. 1. Prisma flow diagram. From: Moher, D., Liberati, A., Tetzlaff, J., Altman, D.G., The PRISMA Group, 2009. Preferred reporting items for systematic reviews and meta-analyses: the PRISMA statement. PLoS Med. 6(6): e1000097. doi:10.1371/journal.pmed1000097.

774


2006). There were also differing definitions of pressure damage with some studies including grade 1 pressure damage (i.e. intact skin with non-blanching erythema) (Catz et al., 2005; Gebhardt et al., 1996; Price et al., 1999; Pham et al., 2011a,b), others grade 2 and above (Iglesias et al., 2006), and in the remaining studies it was unclear (Inman et al., 1993, 1999). High specification foam mattresses were evaluated against low air loss mattresses (Catz et al., 2005) and against a package of care including skin cleaning and nutrition (Pham et al., 2011a). Catz et al. (2005) found that foam mattress system were significantly cheaper if the nursing manpower cost remained constant and the nursing staff were capable of undertaking repositioning every 2.5 h. However, if the nursing staff unable to perform sufficient repositioning, or if nursing costs increased then the low air-loss mattress became more cost-effective. Pham et al. (2011a) found that pressure redistribution high specification foam mattresses were better than standard foam mattresses for long term care residents and that using a foam cleanser and the use of foam cleansers and emollients appeared cost-effective but more clinical data were needed. Different types of dynamic systems were evaluated within the studies. Iglesias et al. (2006) compared alternating mattresses and alternating pressure overlays (these are placed on top of an existing foam mattress). These researchers found that the alternating pressure mattresses were more likely to be cost effective but that the difference was not statistically significant. The alternating pressure mattresses had a lower mean cost of £283.6 per patient linked to a longer time to developing a pressure ulcer and a reduced length of stay for the alternating mattresses. Gebhardt et al. (1996) compared low airloss with alternating pressure mattresses. They found that 4% (1/23) in the alternating-pressure group developed a grade 1 or above pressure ulcer compared with 55% (11/20) in the low-pressure group (p < 0.001, 95% CI: 27–74). Price et al. (1999) compared an inflatable mattress system (Repose) versus a dynamic = mattress for patients undergoing treatment for fractured neck of femur. The researchers found no difference in the efficacy of the air mattress and dynamic mattress in the development of pressure sores or skin condition; however, the inflatable mattress was considerably less expensive. Inman et al. (1993) compared a standard ICU bed and a dynamic air mattress. Those patients on an air mattress were less likely to develop pressure damage compared to those on standard 6/50 and 25/50 respectively). The air mattress was also more cost-effective than frequent patient turning. Inman et al. (1999) compared whether rental or purchased mattress overlay products and found that the purchase strategy cost less. Pham et al. (2011b) used a Markov model based on a review of the literature to compare a static operating table overlays made of a dry, viscoelastic polymer vs the standard operating table mattresses. The model suggested that use of the overlay would decrease the incidence of pressure ulcers by 0.51% and was a cost-effective strategy for patients who had a surgical procedures over 90 min.

5.1.2. Dressings A foam dressing applied to the heel was evaluated by Torra et al. (2009). They compared the application of Softban bandage to heel plus normal pressure ulcer preventing measures vs application of Allevyn Heel foam dressing underneath the Softban. The study reported that Allevyn heel required fewer dressing changes and the cost per ulcer avoided was $28.68 using Allevyn in addition to the Softban bandage. 5.1.3. Other prevention strategies Two studies examined multi-stranded prevention strategies. One study compared three strategies used in different hospitals (Bostrom et al., 1996). The three sites had overlapping components with variations in their uptake. These were: mattress pads, absorbant pads (Chux), pillows to offload heels, eggcrate mattress, disposable nappies (diapers) and hand lotion. Costs and the incidence of pressure ulcers were similar between the sites. The only intervention found to have any significance was that the higher the number of layers of bedding increased the likelihood of skin breakdown. Interestingly, study also found that the Braden Score (Bostrom et al., 1996, 205–210) was not predictive of skin breakdown. Schuurman et al. (2009) used data based on a cohort study to examine whether a ‘‘technological approach’’ utilising mattresses, dressings, ointments vs the ‘‘human approach’’ using repositioning and mobilisation were best in the prevention of pressure ulcers. There was no difference in the incidence of pressure ulcers between the two groups but the technical approach was found to be less expensive. 6. Findings of the treatment studies 6.1. Dressings Eight of the studies examined wound dressings for the treatment of pressure ulcers (Bergemann et al., 1999; Colwell et al., 1993; Graumlich et al., 2003; Muller et al., 2001; Ohura et al., 2004; Payne et al., 2009; Small et al., 2002; Xakellis and Chrischilles, 1992). Five of the studies were conducted within the hospitals setting (Bergemann et al., 1999; Colwell et al., 1993; Ohura et al., 2004; Payne et al., 2009), one in an intermediate long terms care facility (Xakellis and Chrischilles, 1992), one in the community setting (Small et al., 2002) and one in nursing homes (Graumlich et al., 2003). There was a wide variation in terms of the size and grade of the ulcer included within the studies: three studies included grades 2–4 (Ohura et al., 2004; Small et al., 2002; Xakellis and Chrischilles, 1992), two only grade 2 and 3 ulcers (Colwell et al., 1993; Graumlich et al., 2003), one only grade 2 ulcers (Payne et al., 2009), and in one it was unclear (Bergemann et al., 1999). The majority of the studies had ulcer healing as the primary outcome measure but two used improvement (Ohura et al., 2004) and rate of healing (Muller et al., 2001). The time allowed for healing varied from four weeks (Payne et al., 2009) to discharge from hospital (Bergemann et al., 1999).


6.2. Hydrocolloid dressings versus other dressings Four studies compared hydrocolloid dressings (HCD) with other dressings or gauze (Colwell et al., 1993; Graumlich et al., 2003; Muller et al., 2001). Colwell et al. (1993) was a randomised controlled trial that enrolled n = 94 patients to the study but only analysed n = 70 patients with n = 97 ulcers. Ulcers were randomised to either HCD or moist wet to dry gauze dressings. The unit of analysis was the ulcer and not the patient and the trial duration 8 weeks. The allocation of the treatment was unbalanced with significantly more grade 3 ulcers in gauze group. The study reported that the HCD was more costeffective than gauze based on it taking less time per day to undertake the dressing the dressing and that there was a higher chance of healing in the HCD group (n = 11 compared to n = 1 in the gauze group. Graumlich et al. (2003) was a RCT with an 8-week follow-up which compared HCD with topical collagen. Thirty patients had hydrocolloid dressing applied twice weekly and 35 patients topical collagen daily. The study was conducted within 11 nursing homes. No difference in healing was found between the two dressings and collagen treatment was reported as being more expensive than HCD. Muller et al. (2001) was a RCT with n = 24 participants who were followed up for 10 weeks. They compared HCD with a collagenase-containing ointment for grade 4 pressure ulcers on the heel. All of the participants were female who had undergone orthopaedic surgery for a fractured neck of femur. Following surgical debridement patients were randomised to either the application of HCD hydrocolloid dressing twice a week (n = 12) or daily application of a collagenase ointment (n = 12) with paraffin gauze and absorbent bandages. The average costs per patient within the HCD group were 5% higher than those with the collagenase and wound healing occurred within a shorter time period (10 weeks) compared to 14 weeks in the HCD group. Xakellis and Chrischilles (1992) was a RCT which patients in a long terms care facility with grades 2–4 ulcers were randomised to either HCD (n = 18) or moist wet to dry gauze dressings (n = 21). Patients were followed up until healing or lost to follow-up. No difference in was found in terms of time to healing or cost of the treatments. However, HCD were associated with a significant saving in nursing time.

775

wound dressing in combination with enzymatic wound cleaning (with collagenase) for the first seven days. The researchers reported that hydroactive dressing and enzymatic wound cleaner had higher material costs compared with gauze and calcium alginate dressings. However, when personnel costs were included in the model there was a significant reduction in cost linked to shorter duration of treatments and less nurses being needed to provide treatments. Ohura et al. (2004) conducted a 12 week prospective costing study, which included 13 acute hospitals. After excluding 8 dropouts, 83 patients were included in the final analysis. The researchers compared modern dressings, manufactured by Convatec, as a group with ‘‘traditional materials’’ used in hospitals in Japan. The modern dressings included hydrocolloid dressings (DuoDerm), gel dressings (Granugel), and a hydrofibre dressing (Aquacel). The traditional materials consisted of ointments and creams (tretinoin tocoferil ointment (Olcenon), alprostadil ointment (Prostandin), bucladesine sodium ointment (Actosin ointment), a mixture of Bromelain Ointment and silver sulfadiazine 1% cream (Geben Cream). The study reported that clinical outcomes were better in the modern dressing group and that the costs were lower linked to less time and personnel needed for the modern dressing group. This study was funded by the manufacturer Convatec. Small et al. (2002) conducted a prospective randomised controlled trial in a community setting within South Africa for patients with grade 2 ulcers. The investigators compared a group of dressings manufactured by Smith and Nephew (IntraSite hydrogel, Allevyn foam, Allevyn adhesive film and OpSite film dressing) and non-Smith and Nephew dressings in common use within the community setting (cotton wool, alginates, hyrocolloids, medicated gauze dressings and gauze). Patients were followed up for a maximum of six weeks. A total of 28 patients were allocated to the Smith and Nephew dressings and n = 30 patients to the standard dressing group. A total of 15 patients in the Smith and Nephew group healed compared to nine in the other group. The study reported no statistically significant difference between the groups as far as cost-effectiveness was concerned but stated that there was a ‘‘tendency’’ for the standard group to be more expensive. 6.4. Foam dressings versus gauze

6.3. Advanced dressings versus standard dressings Two studies compared advanced dressings against standard dressings and treatments (Bergemann et al., 1999; Graumlich et al., 2003; Small et al., 2002). Bergemann et al. (1999) examined five different dressing treatment strategies for both pressure ulcers and leg ulcers using a mathematical model populated with data obtained from German acute hospitals. The treatment strategies were: gauze with Ringers solution (an isotonic solution), enzymatic ointment impregnated gauze wound dressing; calcium alginate dressing, hydroactive (Cutinova hydro, Smith and Nephew) wound dressing in combination with enzymatic wound cleaning (collagenase) and hydroactive

One group compared a foam dressing with gauze (Payne et al. (2009)) in a mixed acute, community and long term setting. The study was supported by the manufacturer Smith and Nephew and two of the co-authors were their employees. A total of 36 patients were randomised between a foam dressing (n = 20) and saline soaked gauze (n = 16). A sample size calculation was performed from which it was estimated a minimum of 19 participants were needed in each group to determine a cost difference of $10 per week between the groups but this was not achieved due to recruitment issues. The study reported lower weekly costs in the foam group compared to the gauze group linked to fewer dressing changes in the foam group.

776

Table 4 Quality of the reporting of prevention studies. Title identified as economic evaluation

Country

Year

Structured Abstract

Intro provides context

Clear study question

Population characteristics

Setting and location

Study perspective

Comparators described

Time horizon

Discount rate

Outcomes and relevance

Measurement Effectiveness

Measurement of effectiveness

Bostrom Catz Forni Gebhard Pham a Pham b Price Schuurm Bou Gilcrea Inman e Iglesia

N Y N N Y Y N Y N N N Y

USA Israel Italy UK Canada Canada UK Netherlands USA Canada Canada UK

1996 2005 2011 1996 2011 2011 1999 2009 2005 1999 1993 2006

N N N N N N N N N N N Y

Y Y Y Y N Y Y Y Y Y Y Y

Y Y Y Y Y Y Y Y Y Y Y Y

Y N Y Y Y Y Y N Y N Y Y

N Y Y Y Y Y Y Y Y N Y Y

N N N N Y Y N Y N N N Y

Y Y Y N Y Y Y Y Y Y Y Y

N N N N N Y N N N N N Y

N N N N Y Y N N N N N Y

N Y N Y Y Y Y Y Y Y Y Y

N N N N – – N N N N N Y

– – – – N Y – – – – – –

Study

Funding Potential Heterogeneity Findings Model Model Analysis Parameters Incremental Sensitivity Currency, Model Costs (unit Costs Pref source conflict and Assumptions methods of values costs of incremental sensitivity explained choice costs and model date and based of limitations analysis costs outcomes methods) based conversion described interest studies

Number out of items included


– – – – N Y – – – – – –

5/23 6/23 8/23 6/23 16/24 20/24 6/23 6/23 7/23 5/23 10/23 23/23


– – – – Y Y – – – – – –

N Y N N N N N N Y N N Y

N N N N Y Y N N N N Y Y

Note: Dashes (–) represent items not applicable to the study.






– – – – Y Y – N – – N –


Y N Y Y Y Y N N N Y Y Y

N N Y N Y Y N N N N Y Y

N N Y N Y N N N N N Y Y


Study

Table 5 Quality reporting treatment studies. Title identified as economic evaluation

Country

Year

Structured Abstract





Study perspective


Time horizon

Discount rate




Mitt Berg Ferr Small Gruam Muller Ohura Colwell Strauss Payne Xak

Y Y Y N N Y Y Y N Y Y

Canada Germany USA South Africa USA Netherlands Japan USA USA USA USA

2011 1999 1995 2002 2003 2001 2004 1993 1991 2009 1992

Y N N N Y Y N N N N N

Y N Y Y Y Y N Y Y Y Y

Y N Y N N N Y N Y N Y

Y Y Y N Y Y N N Y N Y

Y N Y Y Y Y N N N N N

Y Y Y N N Y N N Y N N

Y Y Y Y Y Y Y Y Y Y Y

Y N N N N N N N N N N


Y Y Y N Y Y N N Y Y Y

– N – N N N N N N N N

N – N – – – – – – – –

Study

Funding Potential Number Heterogeniety Findings Model Model Analysis Parameters Incremental Sensitivity Currency, Model Costs (unit Costs Pref of items source conflict and Assumptions methods of values costs of incremental sensitivity explanined choice costs and model date and based of interest included limitations analysis costs outcomes methods) based conversion described studies


– – – – – – – – – – –

– Y N N N N N N N N N

Y – – – – – – – – – –

Y N N N N N N N N N Y


Note: Dashes (–) represent items not applicable to the study.


N N N N N N N N N N N

Y Y N N N N N N Y N N

Y N N N N Y N N N N N

– N N N N N N N N N N

Y – – – – – – – – – –


Y N N N N N N N Y Y Y


Y N N N Y N N N N Y Y

20/23 6/23 6/23 2/23 7/23 8/23 2/23 2/23 8/23 5/23 8/23


Study

777

778


No difference in time to wound healing was found between the two groups. However, the foam was declared as being more cost-effective as the costs were lower than the gauze group. 6.5. Quality of economic analysis within included studies 6.5.1. Prevention studies The majority of the 12 prevention studies were published outside of the US: five in Europe (three in the UK, one Netherlands and one Italy), four in Canada, one in Israel and two in the US (see Table 3). More articles were published in nursing journals (n = 7) rather than medical journals (n = 5). The sample sizes also tended to be larger than those included studies evaluating treatments for pressure ulcers. The median sample size was 136: ranging from 52 to 19,771. The average number of items on the CHEERS checklist was 10 out of 24 (see Table 4). The basis for the included costs were unclear in the majority of the included studies. There was a reliance on using unit costs based on previously published data or national and locally available data. Only one prevention study used a bottom-up approach to costing with prospective data collected alongside a randomised controlled trial (Iglesias et al., 2006). A bottom-up approach has been found to provide a more accurate estimate of cost compared to a top-down costing as it collects cost data at the patient level compared to using aggregate costs such as hospital or insurance charges (Chapko et al., 2009). The types of economic evaluations varied. Four research teams used data from trials to inform cost-effectiveness analyses (Gebhardt et al., 1996; Iglesias et al., 2006; Inman et al., 1999; Schuurman et al., 2009) but one of these Gebhardt et al. (1996) was a pseudo-randomised trial as it used the hospital as a basis of allocating treatment. Three research teams used decision modelling (Inman et al., 1993; Pham et al., 2011a,b). One team (Catz et al., 2005) undertook a cost-minimisation analysis. However, in the cost-minimisation analysis it was unclear whether there was an adequate demonstration of the equivalence of

the two interventions (air versus foam mattress) to justify using such an approach. 6.5.2. Treatment studies The majority of the 11 treatment studies were published in the US (n = 6); two in Europe (one Netherlands and one Germany), and two outside Europe (see Table 3). The journals the studies were published in were mostly aimed at medical staff with only n = 3 published in nursing journals. The studies tended to have a small sample size, with the number of participants ranging from 24 to 120 (median = 64). There was a tendency (7 out of 11) of the studies evaluating treatment to be funded by industry compared to those evaluating prevention (3 out of 15). The average CHEERS checklist criteria included in the studies was 8 out of 24 (see Table 5). For the treatment studies: two (Payne et al., 2009; Small et al., 2002) used data from randomised controlled trials to undertake cost-effectiveness analyses; seven (Colwell et al., 1993; Graumlich et al., 2003; Muller et al., 2001; Ohura et al., 2004; Payne et al., 2009; Small et al., 2002; Xakellis and Chrischilles, 1992) included costs as an outcome in a clinical trial; and three used decision modelling (Ferrell et al., 1995; Mittmann et al., 2011). There were four studies (Colwell et al., 1993; Muller et al., 2001; Payne et al., 2009; Xakellis and Chrischilles, 1992) that undertook a micro-costing approach. Two of the studies (Muller et al., 2001; Payne et al., 2009) used prospective logs of dressing time and resources used until healing occurred. However, the other two studies estimated the times and resources based on a subsection of the population or as a point estimate. One research team (Colwell et al., 1993) undertook a two week observation of nursing time and the other (Xakellis and Chrischilles, 1992) observed a random sample of ten patients in each group on one occasion. 6.6. Costing methodology in prevention and treatment studies In terms of the sophistication and quality of the costing analysis for both the included prevention and treatment

Table 6 Average cost per patient in USD and Euros at 2012 prices for studies evaluating prevention. Prevention interventions

Type of cost

Intervention group

Range

Control group

Range

Dynamic mattress (Matrix 2000 vs Foam Mattress and Low airloss 2000) (Catz et al., 2005)

Cost per patient episode of achieving day without PU

$22.51

$30.11–$34.78

Foam $26.17

$22.40–$29.94

s19.63

s26.26–s30.33

s19.53–s26.11 s22.82 $20.17–$24.84 Low airloss mattress $32.44

s17.29–s21.66

Not reported

s28.29 $196.33

Not reported

Alternating pressure mattress vs constant pressure mattress (Gebhardt et al., 1996)

Average support costs per patient

$101.35

Technical vs Human approach to pressure ulcer prevention (Schuurman et al., 2009)

Average cost per day of prevention of pressure ulceration

$14.93

$0.62–$118.25

$27.55

$0.15–$190.58

s13.02

s0.54–s103.11

s24.02

s0.13–s166.

s88.38

Note: All costs data are in 2012 US dollars and Euros.

s171.20


779

Table 7 Average cost per patient in USD and Euros at 2012 prices for studies evaluating treatments. Treatment intervention

Type of cost

Intervention group

Range

Control group

Range

Advanced products vs ‘‘standard’’ products (Small et al., 2002) Collagenase ointment vs hydrocolloid dressing (Muller et al., 2001)

Average cost per patient

$50.93

$105.68–$268.07

$240.92

$199.96–$416.81

Per ulcer healed

s44.41 $1391.28

s92.15to s234.28 $889.75–$1950.20

s210.08 $2101.44

s174.37–s363.45 $1340.50–$2988.82

s1213.20

s775.88–s1700.57

s1832.46

s1168.92–s2606.25

Air fluidized mattress vs ‘‘conventional’’ therapy (Strauss et al., 1991) Hydrocolloid dressing vs moist gauze (Colwell et al., 1993)


$27,741.35

Not reported

$28,392.00

Not reported


s24,190.46 $85.35

Not reported

s24,757.82 $281.27

Not reported

s74.43

studies the majority of the trials were poor as the majority simply totalled up unit product costs rather than derived costs using a bottom-up methodology. In no study did the analysts undertake the recommended incremental analysis, discounting, identify a cost-effectiveness threshold or perform sensitivity analysis. Within the prevention studies, five research teams (Iglesias et al., 2006; Inman et al., 1993; Legood and McInnes, 2005; Pham et al., 2011a,b) out of the 12 performed an incremental analysis, one (Legood and McInnes, 2005) applied discounting to future costs; two (Iglesias et al., 2006; Pham et al., 2011a) applied a costeffectiveness threshold; and six (Iglesias et al., 2006; Inman et al., 1993, 1999; Legood and McInnes, 2005; Pham et al., 2011a,b) undertook sensitivity analysis. Within the treatment studies two teams (Mittmann et al., 2011; Payne et al., 2009) performed an incremental analysis; no researchers applied discounting; one team (Mittmann et al., 2011) identified a cost-effectiveness threshold; and five (Bergemann et al., 1999; Ferrell et al., 1995; Mittmann et al., 2011; Muller et al., 2001; Payne et al., 2009) undertook some form of sensitivity analysis. Few researchers reported more than aggregate costs of treatments with only a small number reporting cost outcomes on the basis of cost per ulcer treated/ prevented. The five studies in the treatment group (Colwell et al., 1993; Muller et al., 2001; Payne et al., 2009; Small et al., 2002; Strauss et al., 1991) and the three (Catz et al., 2005; Gebhardt et al., 1996; Schuurman et al., 2009), that reported individual data are shown in Tables 6 and 7. 7. Discussion This is the first systematic review of economic evaluations assessing interventions aimed at preventing or treating pressure ulcers. The results of the current review highlighted that there were a number of deficiencies with regard to the published economic evidence on both pressure ulcer prevention and treatment. Furthermore, the reporting when assessed against the CHEERS checklist showed poor compliance with most studies including less than half the criteria specified in the checklist. In some cases (Colwell et al., 1993; Ohura et

s245.277

al., 2004) the studies only included two criteria from the checklist. Nearly a third of the studies (30%), that made statements in the abstract or title about cost-effectiveness, on further examination were found to have either no comparator or did not provide sufficient detail regarding included costs. This would seem to confirm a criticism often applied within the wound care field that much of the evidence is directed more at marketing product rather than generating high quality evidence (Madden, 2012). Some of the lack of drive for rigour in regard to pressure ulcer prevention and treatment can be attributed to pressure relieving mattresses and wound dressings being classified as medicinal devices and so requiring a much lower level of evidence prior to their introduction than other treatments such as pharmaceuticals. The majority of studies were also funded or conducted in collaboration with industry: particularly in studies evaluating treatment. The industry funded studies also tended to report positive results for their own product. The potential for bias regarding the presentation and interpretation of the results from these studies was therefore high. The review also found a trend for studies that were evaluating treatments to have been conducted in the US and targeted at medical journals. This contrasted with the prevention studies which tended to be conducted outside of the US and published in journals targeted at nurses. One potential reason for this could be the commercialisation of healthcare in the US and the higher potential market for treatments rather than prevention. In terms of the source of the data regarding costs, the majority of studies based cost estimates on hospital charges rather than collecting bottom up costs. Few of the studies acknowledged the potential limitations of using this source for costs. One particularly important issue may be that the charges could bias cost estimates as charges may differ from real world costs (Graves et al., 2002). Many of the studies simply aggregated costs rather than producing cost per ulcer. The review did highlight that the old adage of ‘‘prevention being better than treatment’’ holds true. Those interventions directed at the prevention of pressure ulcers were several times less expensive than those treating them once they had occurred.

780


The time horizon was not reported in the majority of the included studies. Where it was reported this tended to be less than 1 year. The use of a short time horizon for the treatment of pressure ulcers may be appropriate for less severe ulcers but may underestimate the costs associated with more severe Grades 3 and 4 ulcers which may take a protracted time to heal. In evaluating interventions for the prevention of pressure ulcers a time horizon longer than a year may be necessary in order to estimate the on-going costs associated with maintenance and support of equipment such as beds and mattresses. A related issue was that few of the studies applied discounting or adjusted for inflation. This may be particularly important within prevention studies where the expected lifetime of the equipment will need to be incorporated into any estimates of effectiveness. There were a number of studies that used modelling to explore interventions. There were problem in terms of the studies reporting sufficient detail regarding the model assumptions, inputs, sensitivity analysis etc. Only two studies (Iglesias et al., 2006; Mittmann et al., 2011) provided the necessary detail as specified in the BMJ guidance on economic models (Stavros and Alastair, 2011). The studies were heterogeneous in terms of factors including country of origin, and sample selection (see Tables A1 and A2). The majority of studies related within the prevention category (n = 9) evaluated different types of beds and mattresses. There seemed to be a clear benefit for the use of alternating pressure mattresses over standard foam and mattress overlays. Iglesias et al. (2006) and Gebhardt et al. (1996) both reported that alternating pressure mattresses were associated with lower costs and better outcomes than other mattress types. However, there appeared to be no clear benefit for other interventions supplementing the mattress type. Nutritional interventions, emollients, skin cleansers, heel protectors and pads all showed no additional effect on reducing the occurrence of pressure ulcers. One intriguing finding implied from Catz et al. (2005) and Schuurman et al. (2009) was that the use of air loss mattresses was better than relying on nursing staff to reposition patients particularly when associated with the increased cost of staff. The findings from those studies evaluating treatments were less clear cut. Wound dressings were found to be similar in terms of costs and healing with no statistically significant findings apart from modern dressings being more effective than ‘‘traditional’’ remedies. This confirms the findings of other systematic reviews in wound care which indicate that the key criteria in healing wounds is through the addressing of the underlying cause of the wound. This is particularly important in the case of pressure ulcers as if there is no reduction in the pressure being applied to the patients tissues then healing is unlikely to be achieved. 7.1. Implications for clinical practice and future research The increasing focus on cost-effectiveness of interventions within wound care mean that there is a need for careful evaluation of the rigour of the evidence that is being presented by manufacturers to justify their use by

health care providers. This review has highlighted that much of the published literature is of poor quality and that there is often a lack of good quality economic evaluations of both the prevention and treatment of pressure ulcers. There was also significant heterogeneity found within the studies included in the current review in terms of costing strategies, clinical setting, patient comorbidities, trial length and classification of pressure ulceration. The relatively poor evidence found in the current review regarding those studies examining the cost of interventions to prevent and treat pressure ulcers mirrors the poor state of the evidence within the wound care field. The lack of rigour, influence of industry and dearth of comparative trials have been highlighted previously (Chou et al., 2013; Dugdall and Watson, 2009; Trueman and Posnett, 2006). This may be due to cost-effectiveness studies and randomised controlled trials for pressure ulcers, and wounds in general, being difficult to conduct, time consuming and expensive. There may also be a lack of funding available for wound studies from non-commercial sources. The support of industry within published and unpublished studies has also been highlighted as a potential problem in terms of the perception of bias – particularly when companies are funding research into their own products (Peinemann et al., 2008). One explanation for the lack of high quality evidence that the interventions are cost-effective may be that wound dressings and pressure relieving devices are medical devices and so manufacturers are not required by many regulators to provide the same level of evidence as pharmaceutical products (Cohen et al., 2007). Medical devices have to prove little more than that they work as described and do not harm the user. The situation has been criticised as being ambiguous, nebulous, and opaque (Campillo-Artero, 2013). The key message from the evidence for the prevention of pressure ulcers was the importance of reducing the applied pressure at the level of the patient’s tissues. This could be achieved through high specification foam mattresses, dynamic mattresses or regular turning by clinical staff. High quality studies were found that alternating pressure mattresses were effective in preventing pressure ulcers (Iglesias et al., 2006) but the evidence for the other interventions was not as robust. The complex and multi-faceted nature of effective pressure ulcer prevention strategies has been highlighted previously (Bergquist-Beringer et al., 2013). Such programmes need to include staff education, identification of at risk patients, focusing on the process of care, pressure relief care strategies, skin assessment, the skill mix of staff and access to pressure relieving equipment. Even when such programmes are resourced and implemented they still may not result in sustainable reductions in the prevalence of pressure ulcers (Niederhauser et al., 2012). The reliance on mechanical means of reducing pressure such as dynamic mattresses and offloading boots may mean that the basic need to turn and assess the patient’s skin for pressure damage may be neglected. This may also go some way to explain the link between the number of registered nurses (RNs) and incidence of pressure ulcers experienced in the acute setting (Stone et al., 2007).


781

comprehensive however it is still possible that some studies were missed. As with all searches of the published literature there may be publication bias and unpublished studies could affect the study findings. The concentration on cost as an inclusion criterion may have meant that studies including other important outcomes were excluded. The exclusion of those articles with no English translation may mean that important cost-effectiveness studies published non-English journals were excluded from the review. Conflict of interest: None declared. Funding: The study was funded by the UK National Institute for Health Research (NIHR) CAT CL 10-006 as part of a Clinical Lectureship. The views expressed are those of the author(s) and not necessarily those of the NHS, the NIHR or the UK Department of Health.

The interventions included in the review which examined treatments for pressure ulcers were mostly focused on different types of wound dressings. These studies tended not to describe the other interventions which could have influenced the healing of the ulcer and may have been confounded by variations in pressure relieving strategies. The studies included in this review tended to undertake unsophisticated costing of the interventions with the majority reporting merely aggregate costs rather than having clear descriptions of what was included and how costs were calculated. There is a need for rigorous economic evaluation of the interventions and treatments for pressure ulcers. We encourage journals to adapt the CHEERS checklist and we encourage researchers to follow these standards. 8. Study limitations

Appendix The search for studies included the major electronic databases and every effort was made to ensure that it was

See Tables A3 and A4.

Table A1 Summary of studies evaluating prevention. Study

Year

Type of study

Intervention/ comparison

Country of study

Time horizon

Findings

Bostrom et al. (1996)

1996

Prevalence survey with costing of prevention protocols

US

Not reported

Catz et al. (2005)

2005

Cost-minimisation analysis

Three prevention strategies based on presence or absence of: 1. Standard mattress, 2. Standard bed sheet, 3. Mattress pad, 4. Chux, 5. Pillow, 6. Eggcrate mattress, 7. Disposable diapers, 8. Hand lotion, 9. Clothing. Low airloss mattress vs foam ‘‘egg carton’’ mattress vs foam mattress

Israel

10 years

Gebhardt et al. (1996)

1996

Cost-effectiveness analysis alongside pseudorandomised trial (used of hospital number to allocate) for n = 56 patients

Constant lowpressure versus alternatingpressure support systems

UK

Not reported

Gilcreast et al. (2005)

2005

RCT

Compared HighCushion Kodel Heel Protector (bunny boot), Egg Crate Heel Lift Positioner (egg crate), or EHOB Foot Waffle Air Cushion (foot waffle).

US

Not reported

Braden Score was not predictive of skin breakdown. Costs of different types of treatments: supplies, specialty beds, used to prevent skin breakdown were not found to be significant predictors of skin breakdown The only intervention found to have any significance was that the higher the number of layers of bedding increased the likelihood of skin breakdown. No significant difference between different protocols for prevention in terms of standard mattress, lotion Foam mattress system is significantly cheaper if the nursing manpower cost is constant and the nursing staff are capable of undertaking pressure area care via repositioning. But if the nursing staff unable to perform sufficient repositioning, or if nursing costs are higher then it is the computerised mattress which more cost-effective Constant low-pressure versus alternating-pressure support systems in the intensive care unit (ICU). Mean support costs per patient were estimated to be 44.50 in the alternating-pressure group and 86.20 in the constant lowpressure group. The alternating-pressure system was associated with lower costs and higher benefits Found no significant difference in incidence of pressure ulcers between the three groups. Defined cost-effectiveness as lowest incidence of heel pressure ulcers at the lowest financial cost to the hospital. Calculated that the bunny boot with pillows would have resulted in $2380.80 savings compared to the other interventions.


782 Table A1 (Continued ) Study

Year

Type of study


Country of study

Time horizon

Findings

Iglesias et al. (2006)

2006

Cost-effectiveness analysis alongside RCT

Compared alternating pressure mattresses with alternating pressure overlays

UK

Yes–states less than 1 year

Inman et al. (1993)

1993

Cost-effectiveness study alongside RCT

Air suspension bed vs a standard intensive care unit bed.

Canada

Not reported

Inman et al. (1999)

1999

RCT with economic evaluation

Purchase vs purchase rent model of mattress provision

Canada

Not reported

Found that alternating pressure mattresses were associated with lower overall costs (£283.6 per patient on average, 95% CI £377.59, £976.79) due to reduced length of stay. Concluded that Alternating pressure mattresses were more likely to be cost effective and more acceptable to patients than alternating pressure overlays. Patients assigned to either an air suspension bed or a standard intensive care unit bed. A total of six patients treated on an air suspension bed developed pressure ulcers compared with 25 patients on a standard bed. Using costs in Canada and USA the air suspension bed proved to be a dominant providing a more clinically effective treatment less expensively than the traditional approach of frequent patient rotation. The cost-effectiveness ratios and sensitivity analysis of cost estimates calculating cost per pressure ulcer prevented the air suspension bed dominant apart from in the Canadian if treatment costs were 75% of estimated costs. Patients randomised to either the experimental group (placed on purchase products) versus control (placed on standard products within ICU which may be either rented or purchased). It was unclear as to which types of mattresses were in each group. A decision model and logistic regression were used to analyse the results. The incidence of pressure ulcers, severity and cost were included as outcomes. No statistically significant differences were reported in the incidence of pressure ulcers in the two groups. Pressure ulcer development was related to the length of stay and Skin Ulcer Risk Evaluation (SURE) Score.

Pham et al. (2011a)

2011

Markov model of cost-effectiveness

Compared four strategies for prevention: 1. pressure redistribution mattresses for all residents, 2. oral nutritional supplements for high-risk residents, 3. skin emollients, 4. foam cleansing for incontinent patients.

Canada

Not reported

The purchase strategy was less costly than the purchase/rent strategy with a cost saving of$95 Canadian dollars per at risk patient. Based on the number of patients which had been through the ICU in the last 10 years the authors estimate that there would be have been a $47,500 CD saving. Strategy 1 and 4 minimally improved QALY gain and reduced the mean lifetime cost by $115 and $179 per resident, respectively. The cost per QALY gained was approximately $78 000 for strategy 3 and $7.8 million for strategy 2. If $50 000 is used a threshold per QALY gained, the probability that improving prevention is cost-effective is 82% for strategy 1, 1% for strategy 2, 43% strategy 3, and 94% strategy 4.


783

Table A1 (Continued ) Study

Year

Type of study


Country of study

Time horizon

Findings

Pham et al. (2011b)

2011

Markov model of cost-effectiveness

Operating table overlays made of dry, viscoelastic polymer vs standard mattresses.

Canada

1 year

Price et al. (1999)

1999

RCT (n = 80)

Inflatable mattress system (Repose) vs a dynamic flotation mattress (Nimbus 2) for patients undergoing treatment for #NoF

UK

Not reported

Schuurman et al. (2009)

2009

Cost minimisation study alongside prospective cohort study on the incidence and risk factors for pressure ulcers.

Compared a technological approach vs the human approach in the prevention of PU

Netherlands

Not reported

Torra et al. (2009)

2009

Cost-effectiveness of RCT conducted in Spain and applied to Canada

Comparing application of Softban bandage to heel plus normal pressure ulcer preventing measures vs application of foam dressing (Allevyn Heel) underneath the softban.

Canada

Not reported

A Markov cohort model evaluated the cost-effectiveness of an intraoperative prevention strategy with operating table overlays made of dry, viscoelastic polymer versus standard mattresses. The cost savings was $46 per patient (range $13 to $116 by surgical population). Intraoperative prevention was 99% likely to be more cost-effective than the standard practice. Used unit costs to evaluate different the cost of providing an inflatable mattress system (Repose) versus a dynamic flotation mattress (Nimbus 2) for patients undergoing treatment for fractured neck of femur (#NoF) The inflatable system cost less than £5000 (1998 prices), which was less than 50% of the cost quoted for providing the alternating-pressure system. Concludes that Repose had similar level of benefit in prevention to dynamic system appears to offer a similar level of benefit. Pressure ulcer prevention through technical approach resulted in a similar incidence rate as prevention through a human approach but the technical approach was less expensive. The mean cost for the technical approach of prevention per day was s13 (95% CI: s8– s18, range s0.54–s103) and s24 (95% CI: s17–s30; range s0.13–s166) for the human approach. Allevyn heel required fewer dressing changes than no dressing and took less time. Cost per ulcer avoided $28.68 using Allevyn. There may be methodological problems in that the costings were based on a RCT conducted in Europe and applied to Canadian healthcare system.

Table A2 Summary of studies evaluating treatment of pressure ulcers. Study

Year

Type of study


Country of study

Time horizon

Findings

Bergemann et al. (1999)

1999

Decision model

Hydroactive dressing vs Gauze dressing

Germany

Not reported

Colwell et al. (1993)

1993

RCT

Moist gauze dressing vs hydrocolloid dressing Tertiary care centre for grade 2 and 3 PU

US

Not reported

Ferrell et al. (1995)

1995

Decision model based on reanalysis of RCT data

Low air loss beds vs standard beds

US

Not reported

Cost saving per case were DM1196-9826 using hydroactive dressing instead of gauze HCD more cost-effective based on it taking less time per day to undertake the dressing. Healing of 11 in HCD compared to 1 in gauze Significantly more in HCD group and more grade 3 ulcers in gauze group Low airloss beds costeffective for patients with ‘‘good’’ healing characteristics and mild ulcers


784 Table A2 (Continued ) Study

Year

Type of study


Country of study

Time horizon

Findings

Graumlich et al. (2003)

2003

RCT

Collagen dressing vs hydrocolloid

US

Not reported

Mittmann et al. (2011)

2011

Decision model

Electrical stimulation plus standard wound care vs standard wound care

Canada

1 year

Muller et al. (2001)

2001

Cost-effectiveness study of RCT conducted in 1995

Netherlands

Not reported

Ohura et al. (2004)

2004

Non-randomised comparative study

Japan (Translation published in USA Journal)

Not reported

Cost of care with Grade 2 and 3 was more cost-effective in Group 1

Payne et al. (2009)

2009

RCT with cost data collected alongside

Collagenase ointment vs hydrocolloid dressing ‘‘1. Modern wound dressings manufactured by Convatec (Hydrocolloids, Aquacel) 2. Traditional materials with a wound protocol (Ointments – Olcernon ointment, alprostadil ointment) Traditional materials with no wound protocol’’ Foam dressing vs saline soaked gauze

No difference in healing between the two dressings. Collagen treatment more expensive. Electrical stimulation + Standard Wound Care was associated with lower average overall costs and better outcomes 16.4% increase in PUs healed and cost saving of $224 Cost saving of 899 Guilders for collagenase ointment

US

Not reported

Small et al. (2002)

2002

RCT and costeffectiveness analysis

South Africa

Not reported

Strauss et al. (1991)

1991

USA

Not reported

Home use of air-fluidized beds sustainable. Patients on airfluidised beds had fewer days in hospital. No significant difference in costs.

Xakellis and Chrischilles (1992)

1992

Non-randomised comparative study of community based patients for 36 week follow-up period RCT with costing

Smith and Nephew advanced wound products vs standard products Air-fluidised bed vs ‘‘conventional’’ therapy

Mean weekly costs lower in foam group with main cost driver frequency of dressing change. No difference in time to healing or healing rates. 95% CI overlap so no difference between groups.

Hydrocolloid dressing vs saline gauze

US

Not reported

No difference in time to healing or costs. Speculates that this was due to the small sample size. Found that difference in costs based on national and local long-term facility rates. HCD associated with a significant saving in nursing time.

Table A3 Quality of the reporting of prevention studies. Title identified as economic evaluation

Country

Year

Structured Abstract





Study perspective


Time horizon

Discount rate




N Y N N Y Y N Y N N N Y

USA Israel Italy UK Canada Canada UK Netherlands USA Canada Canada UK

1996 2005 2011 1996 2011 2011 1999 2009 2005 1999 1993 2006


Y Y Y Y N Y Y Y Y Y Y Y

Y Y Y Y Y Y Y Y Y Y Y Y

Y N Y Y Y Y Y N Y N Y Y

N Y Y Y Y Y Y Y Y N Y Y

N N N N Y Y N Y N N N Y

Y Y Y N Y Y Y Y Y Y Y Y



N Y N Y Y Y Y Y Y Y Y Y

N N N N

Study


N Y N N N N N Y

Funding Potential Heterogeneity Findings Model Model Analysis Parameters Incremental Sensitivity Currency, Model Costs (unit Costs Pref source conflict and Assumptions methods of values costs of incremental sensitivity explained costs and model date and choice based of interest limitations analysis costs outcomes methods) based conversion described studies

Bostrom Catz Forni Gebhard Pham a N Pham b Y Price Schuurm Bou Gilcrea Inman e Iglesia


N Y N N N N N N Y N N Y

N N N N Y Y N N N N Y Y






N

N


Y N Y Y Y Y N N N Y Y Y

N N Y N Y Y N N N N Y Y

N N Y N Y N N N N N Y Y

Number out of items included 5/23 6/23 8/23 6/23 16/24 20/24 6/23 6/23 7/23 5/23 10/23 23/23


Study

785

786

Table A4 Quality reporting treatment studies. Title identified as economic evaluation

Country

Year

Structured Abstract





Study perspective


Time horizon

Discount rate



Y Y Y N N Y Y Y N Y Y

Canada Germany USA South Africa USA Netherlands Japan USA USA USA USA

2011 1999 1995 2002 2003 2001 2004 1993 19,991 2009 1992

Y N N N Y Y N N N N N

Y N Y Y Y Y N Y Y Y Y

Y N Y N N N Y N Y N Y

Y Y Y N Y Y N N Y N Y

Y N Y Y Y Y N N N N N

Y Y Y N N Y N N Y N N

Y Y Y Y Y Y Y Y Y Y Y



Y Y Y N Y Y N N Y Y Y

Study


Costs (unit Pref costs based outcomes and methods) Y N N N N N N N N N




Costs model based studies

Funding Potential Number Heterogeniety Findings Model Model Analysis Parameters Incremental Sensitivity Currency, Model source conflict of of items and Assumptions methods of values costs of incremental sensitivity explanined choice date included interest limitations analysis costs described and conversion

Y

Y N N N N N N N N N Y




Y Y N N N N N N Y N N

Y N N N N Y N N N N N



Y N N N N N N N Y Y Y


Y N N N Y N N N N Y Y

20/23 6/23 6/23 2/23 7/23 8/23 2/23 2/23 8/23 5/23 8/23


Study


References Beeckman, D., Schoonhoven, L., Fletcher, J., Furtado, K., Gunningberg, L., Heyman, H., Lindholm, C., Paquay, L., Verdt, J., Defloor, T., 2007. EPUAP classification system for pressure ulcers: European reliability study. J. Adv. Nurs. 60 (6), 682–691. Bennett, G., Dealey, C., Posnett, J., 2004. The cost of pressure ulcers in the UK. Age Ageing 33 (3), 230–236. Bergemann, R., Lauterbach, K.W., Vanscheidt, W., Neander, K.D., Engst, R., 1999. Economic evaluation of the treatment of chronic wounds – hydroactive wound dressings in combination with enzymatic ointment versus gauze dressings in patients with pressure ulcer and venous leg ulcer in Germany. Pharmacoeconomics 16 (4), 367–377. Bergquist-Beringer, S., Dong, L., He, J., Dunton, N., 2013. Pressure ulcers and prevention among acute care hospitals in the United States. Joint Commission J. Qual. Patient Saf. 39 (9), 404–414. Bostrom, J., Mechanic, J., Lazar, N., Michelson, S., Grant, L., Nomura, L., 1996. Preventing skin breakdown: nursing practices, costs, and outcomes. Appl. Nurs. Res. 9 (4), 184–188. Bouza, C., Saz, Z., Munoz, A., Amate, J.M., 2005. Efficacy of advanced dressings in the treatment of pressure ulcers: a systematic review. J. Wound Care 14 (5), 193–200. Braden, B.J., Bergstrom, N., 1994. Predictive validity of the Braden scale for pressure sore risk in a nursing home population. Res. Nurs. Health 17 (6), 459–470. Brem, H., Maggi, J., Nierman, D., Rolnitzky, L., Bell, D., Rennert, R., Golinko, M., Yan, A., Lyder, C., Vladeck, B., 2010. High cost of stage IV pressure ulcers. Am. J. Surg. 200 (4), 473–477. Briggs, A.H., O’Brien, B.J., 2001. The death of cost-minimization analysis? Health Econ. 10 (2), 179–184. Campillo-Artero, C., 2013. A full-fledged overhaul is needed for a risk and value-based regulation of medical devices in Europe. Health Policy. (Early publication available online http://www.sciencedirect.com/ science/article/pii/S0168851013000821). Catz, A., Zifroni, A., Philo, O., 2005. Economic assessment of pressure sore prevention using a computerized mattress system in patients with spinal cord injury. Disabil. Rehabil. 27 (21), 1315–1319. Chapko, M.K., Liu, C.F., Perkins, M., Li, Y.F., Fortney, J.C., Maciejewski, M.L., 2009. Equivalence of two healthcare costing methods: bottom-up and top-down. Health Econ. 18 (10), 1188–1201. Chou, R., Dana, T., Bougatsos, C., Blazina, I., Starmer, A.J., Reitel, K., Buckley, D.I., 2013. Pressure Ulcer Risk Assessment and PreventionA Systematic Comparative Effectiveness Review. Annals of Internal Medicine 159 (1), 28–38. Cohen, J., Stolk, E., Niezen, M., 2007. The increasingly complex fourth hurdle for pharmaceuticals. Pharmacoeconomics 25 (9), 727–734. Colwell, J.C., Foreman, M.D., Trotter, J.P., 1993. A comparison of the efficacy and cost-effectiveness of two methods of managing pressure ulcers. Decubitus 6 (4), 28–36. Defloor, T., Bacquer, D.D., Grypdonck, M.H.F., 2005. The effect of various combinations of turning and pressure reducing devices on the incidence of pressure ulcers. Int. J. Nurs. Stud. 42 (1), 37–46. Detsky, A.S., Naglie, I.G., 1990. A clinician’s guide to cost-effectiveness analysis. Ann. Intern. Med. 113 (2), 147–154. Drummond, M.F., Jefferson, T.O., 1996. Guidelines for authors and peer reviewers of economic submissions to the BMJ. Br. Med. J. 313, 275–283. Drummond, M.F., Sculpher, M.J., Torrance, C., O’Brien, B.J., Stoddart, G.L., 2005. Methods for the Economic Evaluation of Health Care Programmes. Oxford Medical Publications, Oxford. Dugdall, H., Watson, R., 2009. What is the relationship between nurses attitude to evidence based practice and the selection of wound care procedures? J. Clin. Nurs. 18 (10), 1442–1450. Evers, S., Goossens, M., de Vet, H., van Tulder, M., Ament, A., 2005. Criteria list for assessment of methodological quality of economic evaluations: consensus on health economic criteria. Int. J. Technol. Assess. Health Care 21 (02), 240–245. Ferrell, B.A., Keeler, E., Siu, A.L., Ahn, S.H., Osterweil, D., 1995. Costeffectiveness of low-air-loss beds for treatment of pressure ulcers. J. Gerontol. Ser. A: Biol. Sci. Med. Sci. 50 (3), M141–M146. Freund, D., Dittus, R., 1992. Principles of pharmacoeconomic analysis of drug therapy. Pharmacoeconomics 1 (1), 20–29. Frick, K., Cohen, K., Stone, P.W., 2013. Economic outcomes and analyses in advanced practice nursing. In: Kleinpell, J. (Ed.), Outcome Assessment in Advanced Practice Nursing. Springer Publishing, New York. Gebhardt, K.S., Bliss, M.R., Winwright, P.L., Thomas, J., 1996. Pressurerelieving supports in an ICU. J. Wound Care 5 (3), 116–121. Gilcreast, D.M., Warren, J.B., Yoder, L.H., Clark, J.J., Wilson, J.A., Mays, M.Z., 2005. Research comparing three heel ulcer-prevention devices. J. Wound Ostomy Continence Nurs. 32 (2), 112–120.

787

Graumlich, J.F., Blough, L.S., McLaughlin, R.G., Milbrant, J.C., Calderon, C.L., Agha, S.A., Scheibel, L.W., 2003. Healing pressure ulcers with collagen or hydrocolloid: a randomized, controlled trial. Am. Geriatr. Soc. 51, 147–154. Graves, N., Walker, D., Raine, R., Hutchings, A., Roberts, J.A., 2002. Cost data for individual patients included in clinical studies: no amount of statistical analysis can compensate for inadequate costing methods. Health Econ. 11 (8), 735–739. Husereau, D., Drummond, M., Petrou, S., Carswell, C., Moher, D., Greenberg, D., Augustovski, F., Briggs, A., Mauskopf, J., Loder, E., on behalf of the CHEERS Task Force, 2013. Consolidated Health Economic Evaluation Reporting Standards (CHEERS) statement. BMC Med. 11 (1), 80. Iglesias, C., Nixon, J., Cranny, G., Nelson, E.A., Hawkins, K., Phillips, A., Torgerson, D., Mason, S., Cullum, N., PRESSURE Trial Group, 2006. Pressure relieving support surfaces (PRESSURE) trial: cost effectiveness analysis. Br. Med. J. 332 (7555), 1416. Inman, K.J., Sibbald, W.J., Rutledge, F.S., Clark, B.J., 1993. Clinical utility and cost-effectiveness of an air suspension bed in the prevention of pressure ulcers. J. Am. Med. Assoc. 269 (9), 1139–1143. Inman, K.J., Dymock, K., Fysh, N., Robbins, B., Rutledge, F.S., Sibbald, W.J., 1999. Pressure ulcer prevention: a randomized controlled trial of 2 risk-directed strategies for patient surface assignment. Adv. Wound Care 12 (2), 72. Legood, R., McInnes, E., 2005. Pressure ulcers: guideline development and economic modelling. J. Adv. Nurs. 50 (3), 307–314. Madden, M., 2012. Alienating evidence based medicine vs. innovative medical device marketing: a report on the evidence debate at a Wounds conference. Soc. Sci. Med. 74 (12), 2046–2052. Mittmann, N., Chan, B.C., Craven, B.C., Isogai, P.K., Houghton, P., 2011. Evaluation of the cost-effectiveness of electrical stimulation therapy for pressure ulcers in spinal cord injury. Arch. Phys. Med. Rehabil. 92 (6), 866–872. Moher, D., Liberati, A., Tetzlaff, J., Altman, D.G., 2009. Preferred reporting items for systematic reviews and meta-analyses: The PRISMA statement. Ann. Intern. Med. 151 (4), 264–269. Moore, Z., Cowman, S., 2009. Quality of life and pressure ulcers: a literature review. Wounds 5 (1), 65–68. Mueller, C., Karon, S.L., 2004. ANA nurse sensitive quality indicators for long-term care facilities. J. Nurs. Care Qual. 19 (1), 39–47. Muller, E., van Leen, M.W., Bergemann, R., 2001. Economic evaluation of collagenase-containing ointment and hydrocolloid dressing in the treatment of pressure ulcers. Pharmacoeconomics 19 (12), 1209–1216. National Patient Safety Agency, 2011. 10 for 2010: Pressure Ulcers. National Pressure Ulcer Advisory Panel and European Pressure Ulcers Advisory Panel, 2009. NPUAP-EPUAP Pressure Ulcer Prevention and Treatment Guidelines. National Pressure Ulcer Advisory Panel, Washington, DC. Niederhauser, A., VanDeusen Lukas, C., Parker, V., Ayello, E.A., Zulkowski, K., Berlowitz, D., 2012. Comprehensive Programs for Preventing Pressure Ulcers: A Review of the Literature. Advances in Skin & Wound Care 25 (4), 167–188. Ohura, T., Sanada, H., Mino, Y., 2004. Clinical study using activity-based costing to assess cost-effectiveness of a wound management system utilizing modern dressings in comparison with traditional wound care. Jpn. J. Geriatr. 41 (1), 82–91 (Japanese). Payne, W.G., Posnett, J., Alvarez, O., Brown-Etris, M., Jameson, G., Wolcott, R., Dharma, H., Hartwell, S., Ochs, D., 2009. A prospective, randomized clinical trial to assess the cost-effectiveness of a modern foam dressing versus a traditional saline gauze dressing in the treatment of stage II pressure ulcers. Ostomy Wound Manage. 55 (2), 50–55. Peinemann, McGauran, Sauerland, Lange, 2008. Negative pressure wound therapy: potential publication bias caused by lack of access to unpublished study results data. BMC Med. Res. Methodol. 8, 4. http:// www.biomedcentral.com/1471-2288/8/4 (accessed 10.06.14). Pham, B., Stern, A., Chen, W., Sander, B., John-Baptiste, A., Thein, H.H., Gomes, T., Wodchis, W.P., Bayoumi, A., Machado, M., Carcone, S., Krahn, M., 2011a. Preventing pressure ulcers in long-term care: a cost-effectiveness analysis. Arch. Intern. Med. 171 (20), 1839–1847. Pham, B., Teague, L., Mahoney, J., Goodman, L., Paulden, M., Poss, J., Li, J., Sikich, N.J., Lourenco, R., Ieraci, L., Carcone, S., Krahn, M., 2011. Support surfaces for intraoperative prevention of pressure ulcers in patients undergoing surgery: a cost-effectiveness analysis. Surgery 150 (1), 122–132 (Review). Price, P., Bale, S., Newcombe, R., Harding, K., 1999. Challenging the pressure sore paradigm. J. Wound Care 8 (4), 187–190. Reddy, M., Gill, S.S., Rochon, P.A., 2006. Preventing pressure ulcers: a systematic review. J. Am. Med. Assoc. 296 (8), 974–984.


Schuurman, J.P., Schoonhoven, L., Defloor, T., van Engelshoven, I., van Ramshorst, B., Buskens, E., 2009. Economic evaluation of pressure ulcer care: a cost minimization analysis of preventive strategies. Nurs. Econ. 27 (6), 390. Small, N., Mulder, E., Mackenzie, M.J., Nel, M., 2002. A comparative analysis of pressure sore treatment modalities in community settings. Curationis 25 (1), 74–82. Sorenson, M., Lyons, S., 2009. Quality of life in patients with a pressure ulcer. J. Spinal Cord Med. 32 (4), 456–457. Stavros, P., Alastair, G., 2011. Economic evaluation using decision analytical modelling: design, conduct, analysis, and reporting. Br. Med. J. 342, d1766. Stinson, M., Gillan, C., Porter-Armstrong, A., 2013. A literature review of pressure ulcer prevention: weight shift activity, cost of pressure care and role of the occupational therapist. Br. J. Occup. Ther. 76 (4), 169–178. Stone, P.W., 1998. Methods for conducting and reporting cost-effectiveness analysis in nursing. J. Nurs. Scholarship 30, 229–234. Stone, P.W., Curran, C.R., Bakkan, S., 2002. Economic evidence for evidence based practice. J. Nurs. Scholarship 34, 277–282.

Stone, P.W., Mooney-Kane, C., Larson, E.L., Horan, T., Glance, L.G., Zwanziger, J., Dick, A.W., 2007. Nurse working conditions and patient safety outcomes. Med. Care 45 (6), 571–578. Strauss, M.J., Gong, J., Gary, B.D., Kalsbeek, W.D., Spear, S., 1991. The cost of home air-fluidized therapy for pressure sores. A randomized controlled trial. J. Fam. Pract. 33 (1), 52–59. Torra, I.B., Rueda Lopez, J., Camares, G., Herrero Narvıéz, E., Blanco Blanco, J., Ballest Torralba, J., Martinez-Esparza, E.H., Garc+ a, L.S.M., Soriano, J.V., 2009. Preventing pressure ulcers on the heel: a Canadian cost study. Dermatol. Nurs. Dermatol. Nurs. Assoc. 21 (5), 268–272. Touche Ross, 1994. The Costs of Pressure Sores (Report to the Department of Health). Touche Ross & Co., London. Trueman, P., Posnett, J., 2006. What price wound care? Int. J. Lower Extremity Wounds 5 (4), 230–232. Waterlow, J., 1991. A policy that protects. The waterlow pressure sore prevention/treatment policy. Prof. Nurse 6 (5), 258–264. Xakellis, G.C., Chrischilles, E.A., 1992. Hydrocolloid versus saline-gauze dressings in treating pressure ulcers: a cost-effectiveness analysis. Arch. Phys. Med. Rehabil. 73 (5), 463–469. !

788

Nutritional interventions for preventing and treating pressure ulcers.

[Economic cost of treating pressure ulcers: a theoretical approach].

Cost effectiveness of medication adherence-enhancing interventions: a systematic review of trial-based economic evaluations.

Economic evaluations of clinical pharmacist interventions on hospital inpatients: a systematic review of recent literature.

A Systematic Review of Health Economic Evaluations of Diagnostic Biomarkers.

Economic evaluations of implantable cardioverter defibrillators: a systematic review.

Economic evaluations in gastroenterology in Brazil: A systematic review.

The Use of the Braden Scale in Assessing Pressure Ulcers in Turkey: A Systematic Review.

Repositioning for treating pressure ulcers.

What is the economic evidence for mHealth? A systematic review of economic evaluations of mHealth solutions.

Interventions for preventing relapse or recurrence of depression in primary health care settings: A systematic review.

Treating pressure ulcers with a myocutaneous flap.

Public health interventions: evaluating the economic evaluations.

A systematic review of modelling approaches in economic evaluations of health interventions for drug and alcohol problems.

Economic evaluations of guideline-based or strategic interventions for the prevention or treatment of chronic wounds.

Interventions aimed at increasing the level of physical activity by including organised follow-up: a systematic review of effect.

Organ and tissue donation in clinical settings: a systematic review of the impact of interventions aimed at health professionals.

ECONOMIC EVALUATIONS OF INTERVENTIONS FOR TRANSTIBIAL AMPUTEES: A SCOPING REVIEW OF COMPARATIVE STUDIES.

A systematic review of interventions aimed at increasing physical activity in adults with chronic musculoskeletal pain--protocol.

Massage therapy for preventing pressure ulcers.

or increasing knowledge among pregnant women.

Hydrogel dressings for treating pressure ulcers.

Economic Evaluations Comparing a Trial of Labor with an Elective Repeat Cesarean Delivery: A Systematic Review.

Health economic evaluations of medical devices in the People's Republic of China: A systematic literature review.