Literature Evaluation Table In nursing practice, accurate identification and application of research is essential to achieving successful outcomes. The ability to articulate research data and summari

Methods Study design, setting and participants The HTA was based on a literature review and original data from an observational study testing two types of overlays.

This article focuses on the observational study. Two types of overlay were tested from August 2017 to January 2018.

We used a high-density viscoelastic foam overlay (Tempur - Topper7, TEMPUR-MED, Denmark) and a thermoplastic polyurethane overlay (Stimulite, Zibo Care, Denmark) as alternatives to AAM (Sentry, Hospitech, Denmark). Box 1 g ives examples of comparable overlays. For patients with a medium ABSTRACT Introduction: At Odense University Hospital (OUH) alternating-air mattresses (AAM) are used in the prevention of pressure ulcers (PU); however, static overlays might be more effective and have lower costs. To investigate the properties and consequences of using static overlays for prevention of PU at OUH, a hospital-based health technology assessment (HTA) was conducted.

Methods: Two types of static overlays were tested in an observational study and compared with AAM for patients with a medium–high risk of PU in geriatric and orthopaedic wards at OUH. Incidence of PU was investigated 7 months before ( n=720) and 6 months after implementation ( n=837). Staff attitudes were examined in a questionnaire survey ( n=55) and focus group interviews ( n=13). Patients who had tried one of the overlays and the AAM were interviewed ( n=12). Results: No statistical difference in PU incidence was found before and after the implementation of overlays (2.5% before, 2.7% after, P=0.874, n=1557) and no patients lying on overlays developed PU (n=123). Staff had mixed attitudes, but the majority preferred having overlays as an option for their patients. Interviewed patients preferred overlays due to less noise and improved mobility. Conclusion: Both types of overlay are effective in PU prevention. However, overlays introduce challenges for staff and clear guidelines for the selection of support surfaces are needed. Overall, it is recommended that static overlays are considered as an alternative to AAM for PU prevention.

Key words : Pressure ulcer ■ Prevention ■ Health technology assessment ■ Static overlay ■ Alternating-air mattresses Mette Boeg Horup , Project Manager, Centre for Innovative Medical Technology, Odense University Hospital, Denmark Knaerke Soegaard , PhD candidate, Nurse, Department of Plastic Surgery, Odense University Hospital, Denmark, [email protected] Tue Kjølhede , Project Manager, Centre for Innovative Medical Technology, Odense University Hospital, Denmark Aase Fremmelevholm , Pressure Ulcer Specialist Nurse, Department of Plastic Surgery, Odense University Hospital, Denmark Kristian Kidholm , Professor, Centre for Innovative Medical Technology, Odense University Hospital, Denmark Accepted for publication: June 2020 2020 MA Healthcare Ltd PRESSURE ULCERS British Journal of Nursing 2020, Vol 29, No 12: TISSUE VIABILITY SUPPLEMENT S25 to high risk of developing PUs, the overlays were placed on a standard viscoelastic foam mattress and tested as a supplement to standard care, which was the use of AAM for patients at medium-high risk for PU and standard mattresses for patients not at risk. Thus, there were three types of mattress available during the test period. The overlays were used in a geriatric ward (46 beds) and an orthopaedic ward (23 beds). Each ward had overlay types available for two periods of 3 months as described in Figure 1 . PU incidence was investigated in both wards for 7 months (January-July 2017) before the test periods. The HTA study had four aspects: clinical effect (PU incidence); organisational aspects (staff attitudes); patient perspectives; and economic consequences. However, only the first three parts are included in this paper owing to confidential information in the economic analysis.

Inclusion criteria All patients admitted to the two wards in the 7 months prior to implementation of the static overlays and for 6 months after the implementation were included in the study. During the test period, patients lying on AAM on arrival at the ward were moved to a bed with an overlay. The optimal support surface for each patient was chosen at admission by ward nurses and/or a specialist wound care nurse based on risk score (Braden scale; Halfens et al, 2000) and clinical assessment. Some high-risk patients and patients with a category 4 PU remained on AAM for clinical reasons. Patients with PUs at admission were excluded in both periods. Patients lying on a standard mattress on arrival who were moved to a bed with an overlay in the test period were excluded from the study because overlays were meant to replace AAM rather than standard mattresses. Data sources, variables and analyses Clinical effectiveness A specialist wound care nurse examined all admitted patients on the wards for PUs three times a week during the study period and recorded the type of support surface and whether the patient had developed a PU. The average number of hospital days for patients in the two departments was 6 days, and, with examination three times per week, it was possible to examine all patients at the beginning of their hospitalisation and before discharge. Fisher’s exact test was calculated using the statistical software package SPSSv24 to investigate statistical difference in PU incidence before and after implementation of overlays.

Organisational perspectives Staff attitudes were investigated using both a questionnaire survey and semi-structured focus group interviews.

■ Questionnaire : nurses and nurse assistants from the two wards, who had experience with patients lying on an overlay, were invited to participate in the questionnaire survey. The questionnaire was set up using the SurveyXact survey tool and distributed by an email with unique links to the online questionnaire. In order to increase the response rate, three reminders were sent in the first period and two in the second period. We sent 147 questionnaires and Figure 1. Set-up and data collection. The two types of overlays were tested in two different wards in a period of 3 months each. Pressure ulcer incidence was monitored before (7 months) and during the two 3-month test periods. Staff attitude\ s and patient perspectives were investigated at the end of each test period Set -up Orthopaedic ward Geriatric ward Alternating- air mattress ‘Stimulite’ overlay Tempur overlay ‘Tempur’ overlay ‘Stimulite’ overlay Data collection Clinical effects Incidence of pressure ulcers: all admitted patients were examined by a specialist wound care nurse Organisational aspects: staff attitudes Questionnaire survey: round 1 Questionnaire survey: round 2 Focus group interviews Patient perspectives Interviews: round 2 Interviews: round 2 1 Jan 2017 1 Aug 2017 30 Oct 2017 31 Jan 2018 Implementat ion Before Af ter 7 months 3 months 3 months Box 1. Examples of comparable static viscoelastic foam overlays including those used in the health technology assessment Basic Top: ZiboCare Stimulite: ZiboCare TEMPUR – Topper7: TEMPUR-MED Pentaflex: ArjoHuntleigh 2020 MA Healthcare Ltd PRESSURE ULCERS British Journal of Nursing 2020, Vol 29, No 12: TISSUE VIABILITY SUPPLEMENT S27 S26 British Journal of Nursing 2020, Vol 29, No 12: TISSUE VIABILITY SUPPLEMENT received 55 responses. Using a five-point Likert scale, the respondents were asked to assess: (a) the level of difficulty of different tasks when taking care of patients lying on overlays compared with AAM (ie personal care); (b) their agreement with statements regarding the procedure of selection of support surface and patient comfort; and (c) which of the support surfaces they preferred. Data from the questionnaire survey were analysed using descriptive statistics ■ Focus group interviews: 13 informants (nurses, nurse assistants, physiotherapists, occupational therapists and clinical assistants) were questioned about the same topics, as described above, in four multidisciplinary focus group interviews. The interviews were audio recorded, transcribed (non-verbatim), and synthesised into summaries with themes, including the main points and selected citations.

Summaries were sent to all informants for approval. Patient perspectives Patients’ attitudes were investigated in structured in-person interviews by the specialist wound care nurse or an HTA consultant. All patients who had tried both AAM and one overlay, and who were physically and cognitively able were invited to participate. All included patients were aware that they had been lying on both mattresses. Patients were introduced to the investigation and their rights. They were asked which type of support surface they would prefer, followed by questions with defined response categories regarding comfort in relation to softness, noise nuisance, mobility and temperature. Patients also had the opportunity to elaborate on their answers and give further comments.

Ethical approval Verbal informed consent was obtained from all individual patients included in interviews. No personally identifiable information was recorded. According to our regional ethics committee, this type of study did not require ethical approval.

Results Clinical effectiveness In total, 1557 patients were included in the study: 720 patients in the period before implementation (7 months) and 873 patients during the test period (6 months). Some 123 patients used overlays during the study and no statistical difference in PU incidence was found between the periods before and after the implementation of overlays ( n=1557, P=0.874) and no patients lying on overlays developed PU (n=123) ( Table 1 ). Organisational aspects The total response rate for the staff questionnaire survey was 46% (68/147). Of the 68 respondents, 13 had no experience with the overlays, 15 answered both questionnaires (one for each test period) and 40 answered one questionnaire.

Thirteen informants participated in focus group interviews:

three nurses, four nurse assistants, two physiotherapists, one occupational therapist and three clinical assistants. Table 2 summarises the main results from the two study parts within the different themes.

Patient perspectives In total, 12 patients who had tried both an overlay and AAM were interviewed (5 men, 7 women, aged 51–99 years). All interviewed patients, except one, found the overlays comfortable and none was bothered by the noise. In contrast, some informants mentioned that noise could be bothersome with AAM. Patients answered that it was ‘easy to change position on overlays’ or ‘neither difficult nor easy’, whereas most found it difficult on AAM. With regard to temperature, both AAM and overlays seemed suitable. One patient said:

‘It is easier to move around and it fits me well in regards to softness.’ When asked which type of support surface patients would prefer, all except one preferred overlays. One patient replied: ‘The new mattress is perfect.’ Discussion Our aim was to investigate the properties and consequences of implementing static overlays based on an observational study comparing AAM with two different types of static overlay. The results showed no statistical difference in PU incidence and none of the patients on overlays developed PUs during the study period. Overall, the patients were satisfied with the overlays, whereas staff had mixed attitudes because there was a change in working procedures. During care and repositioning, sliding material must be used under the patients because they lie more heavily on overlays. After use, the rented AAM are simply rolled up and returned for cleaning and preparation by the company, but the purchased overlays must be cleaned and prepared by the hospital staff. The staff said that cleaning of overlays was more time consuming, and the majority found personal care more difficult for patients who were lying on overlays compared with those on AAM.

However, they still preferred overlays as an option and thought that they were beneficial for patients. This could possibly be related to the challenges in repositioning experienced with immobile patients. There are many studies on the effect of support surfaces for PU prevention, including several reviews (McInnes et al, 2015; Qaseem et al, 2015; Shi et al, 2018). However, in our literature review, we identified only two studies that compared static overlays with AAM on their effect on PU incidence in hospitals (Andersen et al, 1983; Jiang et Table 1. Incidence of pressure ulcers in the periods before and after implementation of static overlays Support surface Pressure ulcer incidence Standard mattress (n) Alternating- air mattresses (n) Overlay Tempur (n) OverlayStimulite (n) Total * (n) Before implementation (n=729) 1.8% (9) 4.2% (9) — — 2.5% (18) After implementation (n=837) 2.8% (14) 4.2% (9) 0% (0) 0% (0) 2.7% (23) *Fisher’s exact test was calculated in order to investigate statistical difference in pressure ulcer incidence before and after implementation. P=0.874 2020 MA Healthcare Ltd PRESSURE ULCERS British Journal of Nursing 2020, Vol 29, No 12: TISSUE VIABILITY SUPPLEMENT S27 al, 2014). Both studies were RCTs and our results are in alignment with their findings, that is, there was no significant difference in PU incidence between overlays and AAM.

However, Andersen et al was published in 1983 and the support surfaces used then may not be comparable with those used in our study. Both RCTs are of low quality based on the Cochrane risk of bias tool (Higgins et al, 2011) due to ‘unclear risk’ for selection bias (randomisation) in Andersen et al (1983) and unclear risk of ‘performance bias’ (blinding) for both studies. McInnes et al (2015) and Qaseem et al (2015) had similar results as described above, but they did not distinguish between mattresses and overlays in the comparison with AAM. McInnes et al (2015) found that the majority of included studies comparing AAM with ‘constant low pressure mattresses’ showed no difference in PU prevention and concluded that it was unclear which type of support surface was most beneficial. Similarly, Qaseem et al (2015) concluded that there is no difference between AAM and ‘advanced static’ support surfaces, but recommended static support surfaces due to lower costs. Shi et al (2018) also concluded that it was uncertain which type of support surface was most effective in preventing PUs and that there was a need for RCTs investigating the effect of static foam surfaces with powered active air surfaces, including AAM. Nixon et al (2019) compared AAM with high-specification foam mattresses in an RCT and reported no significant difference in PU prevention. Based on our results and those from the literature review, there are no clear indications as to which type of support surfaces are most beneficial with respect to PU prevention.

Thus, there are no clinical arguments for using AAM rather than overlays in PU prevention, but AAM has been the only option and standard of care for patients at risk of developing PUs at our hospital. Limitations This study was an observational comparative study without randomisation and blinding, which affects the internal validity Table 2. Main results from interviews with staff and the questionnaire survey Theme Staff attitude Training in using the support surfaces Not enough information prior to implementation, more information requested about guidelines for selection of support surface Selection of support surface 25% of respondents disagreed with the statement: ‘I never have doubts about what type of support surface the patient should lie on.’ However, only 13% thought that the guidelines/criteria were unclear Working procedures and application ■ Mixed attitudes towards general application and handling of overlays and for making/preparing beds with overlay ■ Clinical assistants thought that cleaning overlays was more time consuming ■ 67% of respondents thought personal care was more difficult for patients lying on overlays ( n=55) ■ For suitable patients (ie patients who could assist with their own repos\ itioning), overlays were considered an advantage for mobilisation. For these patients, repositioning and getting in and out of bed was easier. The overlays were also considered to be safer due to their lower height and less slippery surface ■ For immobile patients who could not help with repositioning, it was more difficult to move them on overlays, due to their surfaces. Alternating-air mattresses (AAM) have smooth surfaces and some informants said they could sometimes reposition patients without the use of a transfer slid\ e sheet Time spent on tasks affected by support surface Informants thought nursing was more time consuming for immobile patients lying on overlays, but unchanged for patients who could assist with their own repositioning Work environment Informants thought immobile patients lying on overlays seemed heavier and more difficult to handle, which could cause long-term physical injuries/discomfort Organisation ■ Overlays should not be used for immobile patients who cannot assist in reposit\ ioning ■ Results were ambiguous when asking whether the overlays were used as intended. Based on interviews, staff thought that overlays were used for the patients for whom they were intended ■ There may have been patients who were not candidates for AAM, but who would have benefited from an overlay ■ There were challenges with logistics and storage of overlays during the test period that should be solved if overlays were to be implemented after the test period Staff assessment of patient experience ■ 47% of respondents believed that overlays were more comfortable for patients compared with AAM ■ Informants found patients to be pleased with the overlays Satisfaction 71% of respondents preferred to have overlays as an option for their patients; however, they are not suitable for all patients and AAM are still needed KEY POINTS ■ There is a general lack of evidence for choice of mattress for pressure ulcer prevention ■ Overlays are a suitable alternative to alternating air mattresses ■ Overlays were preferred by the patients 2020 MA Healthcare Ltd PRESSURE ULCERS S28 British Journal of Nursing 2020, Vol 29, No 12: TISSUE VIABILITY SUPPLEMENT of the study. For example, there may have been an increased focus on PU prevention for patients on overlays and these patients may have been at less risk of developing PU compared with patients on AAM. It was not possible to investigate this further and adjust for any differences in patient groups because we recorded data for PU incidence only. The small number of participants is a limitation of the study. The staff found overlays more time-consuming to clean and the personal care of patients more difficult compared with the use of AAM. This could have affected their responses. The results are uncertain, but in alignment with the results of other studies. We focused on the use of two types of overlay, but there may be other, more beneficial, alternatives to AAM.

Conclusion Despite limitations, the results of the HTA show that overlays are a suitable alternative to AAM for patients with a medium to high risk of developing PUs, since no difference in PU incidence was found and no patients on overlays developed PUs. Furthermore, patients, as well as staff, preferred having overlays as an option. However, the overlays are not suitable for all patients and clear guidelines on the selection of support surfaces are necessary. Organisational challenges, such as more time spent on cleaning, should be taken into consideration before implementation. Further investigation of the economic aspects of using overlays is needed because there could be possible financial benefits.  BJN Declaration of interest: none The interview guide and questionnaire used in the study are available from the corresponding author Andersen KE, Jensen O, Kvorning SA, Bach E. Decubitus prophylaxis: a prospective trial on the efficiency of alternating-pressure air-mattresses and water-mattresses. Acta Derm Venereol. 1983; 63(3):227–230 Bennett G, Dealey C, Posnett J. The cost of pressure ulcers in the UK. Age Ageing. 2004; 33(3):230–235. https://doi.org/10.1093/ageing/afh086 Bermark S, Jensen LB, Krejberg E et al. Seks prævalensundersøgelser for tryksår: øjebliksbilleder fra danske hospitaler. Sår. 2009; 17:203–210 Chou R, Dana T, Bougatsos C et al. Pressure ulcer risk assessment and prevention: a systematic comparative effectiveness review. Ann Intern Med. 2013; 159(1):28–38. https://doi.org/10.7326/0003-4819-159-1-201307020-00006 European Pressure Ulcer Advisory Panel, National Pressure Ulcer Advisory Panel, Pan Pacific Pressure Injury Alliance. Prevention and treatment of pressure ulcers: quick refe rence guide. 2nd edn. 2014. https://tinyurl.com/v3h44b8 (accessed 10 June 2020) Fremmelevholm A, Soegaard K. Pressure ulcer prevention in hospitals: a successful nurse-led clinical quality improvement intervention. Br J Nurs. 2019; 28(6):S6–S11. https://doi.org/10.12968/bjon.2019.28.6.S6 Halfens RJ, Van Achterberg T, Bal RM. Validity and reliability of the Braden scale and the influence of other risk factors: a multi-centre prospective study. Int J Nurs Stud. 2000; 37(4):313–319. https://doi.org/10.1016/s0020-7489(00)00010-9 Higgins JPT, Altman DG, Gøtzsche PC et al. The Cochrane Collaboration’s tool for assessing risk of bias in randomised trials BMJ 2011; 343:d5928. https://doi.org/10.1136/bmj.d5928 Jiang Q, Li X, Zhang A et al. Multicenter comparison of the efficacy on prevention of pressure ulcer in postoperative patients between two types of pressure-relieving mattresses in China. Int J Clin Exp Med. 2014; 7(9):2820–2827 Mathiesen AS, Norgaard K, Andersen MF, Moller KM, Ehlers LH. Are labour- intensive efforts to prevent pressure ulcers cost-effective? J Med Econ. 2013; 16:1238–1245. https://doi.org/ 10.3111/13696998.2013.832256. McInnes E, Jammali-Blasi A, Bell-Syer SE et al. Support surfaces for pressure ulcer prevention. Cochrane Database Syst Rev. 2015; (9):CD001735. https://doi.org/ 10.1002/14651858.CD001735.pub5 Nixon J, Brown S, Smith IL et al. Comparing alternating pressure mattresses and high-specification foam mattresses to prevent pressure ulcers in high-risk patients: the PRESSURE 2 RCT. Health Technol Assess. 2019; 23(52):1–176. https://doi.org/10.3310/hta23520 Qaseem A, Mir TP, Starkey M, Denberg TD; Clinical Guidelines Committee of the American College of Physicians. Risk assessment and prevention of pressure ulcers: a clinical practice guideline from the American College of Physicians. Ann Intern Med. 2015; 162(5):359–369. https://doi.org/10.7326/M14-1567 Shi C, Dumville JC, Cullum N. Support surfaces for pressure ulcer prevention: a network meta-analysis. PLoS One. 2018; 13(2):e0192707. https://doi.org/10.1371/journal.pone.0192707 Vanderwee K, Clark M, Dealey C, Gunningberg L, Defloor T. Pressure ulcer prevalence in Europe: a pilot study. J Eval Clin Pract. 2007; 13(2):227–235. https://doi.org/10.1111/j.1365-2753.2006.00684.x CPD reflective questions ■ Does your hospital have clear guidelines on which overlay to choose for your patients?

■ Is your choice of mattress supported by the scientific literature?

■ Could patient and/or staff satisfaction be improved by using an alternative to the current standard of care?

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