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Higher density foam mattresses and sheepskins reduce risk of pressure ulcers

McInnes E, Jammali-Blasi A, Bell-Syer SEM et al. Support surfaces for pressure ulcer prevention Cochrane Database Syst Rev. 2015:9:CD001735

Review question

Can pressure relieving support surfaces prevent pressure ulcers?


Pressure ulcers are areas of the skin and tissue that are damaged by pressure or friction. Pressure ulcers often affect people who are elderly and immobile causing pain and reduced quality of life. Support surfaces such as beds, mattresses and mattress overlays are used to relieve pressure by distributing the patient’s weight more evenly or varying the duration and applied pressure.

How the review was done

The researchers did a systematic review and meta-analysis of 59 randomised and quasi-randomised trials.

The number of participants in the studies ranged from 12 to 1171.

Key features of the studies were:

  • Participants were receiving health care and were at risk of developing pressure ulcers.
  • Researchers compared the impact of different types of surfaces on the development of pressure ulcers
  • “Low-tech” constant low pressure supports included standard foam mattresses, high density mattresses, gel filled mattresses and sheepskin overlays. “High-tech” supports included alternating-pressure mattresses, which have air-filled sacs that inflate and deflate to relieve pressure.
  • Researchers measured whether patients using different types of support surfaces developed pressure ulcers.

What the researchers found

From 5 studies, researchers found that people who lay on higher specification/density foam mattresses were 60% less likely to develop new pressure ulcers compared to people who lay on regular foam mattresses. From 3 studies, sheepskin overlays on mattresses were also found to prevent the development of pressure ulcers.

Studies focused on other support surfaces like constant low pressure and alternating pressure had a high risk of bias or conflicting results about the benefits for preventing pressure ulcers.  Future studies are needed to measure the benefits of high-tech solutions for preventing pressure ulcers.


Higher density foam mattresses and medical-grade sheepskins help to prevent new pressure ulcers.


Advanced statistical methods contrasting and combining results from different studies.
Risk of bias
Possibility of some systematic error in the studies.
Systematic review
A comprehensive evaluation of the available research evidence on a particular topic.

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DISCLAIMER These summaries are provided for informational purposes only. They are not a substitute for advice from your own health care professional. The summaries may be reproduced for not-for-profit educational purposes only. Any other uses must be approved by the McMaster Optimal Aging Portal (

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