Alternating pressure mattresses were more cost effective than alternating pressure overlays for preventing pressure ulcers

摘要

Pressure relieving support surfaces are widely used to prevent pressure ulcers. These surfaces range from foam mattresses for standard use in vulnerable patients to alternating pressure mattresses for high risk patients. A Cochrane systematic review of 41 RCTs assessed the effectiveness of different pressure relieving surfaces in preventing pressure ulcers and found no clear evidence to support the use of any specific surface.; This result provided the stimulus for the RCT by the UK PRESSURE Trial Group. No previous trial has compared an alternating pressure mattress with an alternating pressure overlay, in terms of pressure ulcer prevention or cost effectiveness. The studies by Iglesias et al and Nixon etal report different outcomes from the same RCT; the study was designed to test both effectiveness and cost effectiveness. The findings of Nixon et al clearly showed no difference between alternating pressure mattresses and overlays in overall pressure ulcer development. However, Iglesias ef al showed that although overlays were cheaper to purchase (approximately 25% of the cost), mattresses were more cost effective in terms of delayed time to pressure ulceration and patient acceptability. The execution of the RCT was as methodologically rigorous as possible, given that it incorporated nurses' ethical decisions on the "best" intervention for individual patients (eg, using a mattress rather than an overlay because of perceived high risk of the patient). It is feasible that mattresses provide the "best" protection when considering purchase cost, brand desirability, and expected quality. More patients in the overlay group requested a change of surface because of discomfort. Strengths of the trial include the large sample of 1972 patients from various locations and specialities and the use of clinically relevant inclusion criteria. The emphasis on the prevention of pressure ulcers was positive. The Braden Scale for risk assessment was a good choice, with reasonable sensitivity and specificity for most at-risk patient groups. Some potential issues and unknown factors in the trial should be considered. Firstly, variations in brands, quality, maintenance, and age of alternating pressure mattresses and overlays would exist within the stocks of different institutions. However, this situation models the reality of health care, and the trial was testing the effect of a policy of pressure prevention as much as it was evaluating pressure devices. Secondly, because care providers were not blinded to patient allocation, questions arise as to whether patients were handled or turned at the same intervals in the mattress and overlay groups. Again, because this was a pragmatic trial, it is likely that any variations in turning were distributed evenly between the groups. Thirdly, Iglesias ef al reported that additional treatment costs were not estimated when a stage 2 pressure ulcer was detected; thus, treatment costs may be underestimated. Despite these limitations, the findings of the PRESSURE trial are a welcome addition of knowledge that can assist healthcare providers in making decisions about purchasing and using pressure relieving devices. Convincingly, the authors believe that the best decision would be for hospitals to use mattresses instead of overlays in acutely ill patients who are deemed "at risk." The crucial point, as stated by Iglesias et al, is that the longer patients avoid ulceration, the less likely they will be to develop a pressure ulcer as their mobility improves.