Foam Surfaces for Preventing Pressure Ulcers
Study by C. Shi, J. C. Dumville, N. Cullum, S. Rhodes and E. McInnes
Cochrane Systematic Review · Cochrane Database of Systematic Reviews (2021, Issue 5, CD013621) · DOI: 10.1002/14651858.CD013621.pub2
Key Takeaway
Standard Foam Did Not Beat Air Surfaces for Preventing Bedsores
What was tested: Cochrane reviewers, who study the combined results of medical trials, looked at 29 randomized trials with 9,566 people. The trials compared foam beds, mattresses or overlays with other surfaces for preventing pressure ulcers, also called bedsores (Shi et al., 2021).
What the numbers showed: Low-certainty evidence suggests foam may raise the risk of new pressure ulcers compared with alternating pressure air surfaces (risk ratio 1.59) and reactive air surfaces (risk ratio 2.40). For the other comparisons, the evidence was too uncertain to say.
What this means for you: This review is about people at risk of bedsores, mostly older hospital patients. It does not show that any home mattress prevents pain or pressure problems in healthy sleepers.
Key Numbers
How the Study Was Done
The reviewers included randomized trials that assigned people of any age to foam beds, mattresses or overlays and compared them with any other surface. They searched medical databases in November 2019 and rated how certain each finding was with a standard grading system (Shi et al., 2021).
Most trials were small, with a middle value of 101 people each, and mainly took place in hospitals. Foam was compared with 7 kinds of surfaces, including air, fiber, gel, water and other types of foam.
What the Review Compared
Air Surfaces (Alternating or Reactive)
Pooled trials suggest fewer new pressure ulcers than on foam, but the evidence is low certainty.
Foam Surfaces
Risk ratio 1.59 against alternating air and 2.40 against reactive air. Above 1 means a higher risk on foam.
What the Study Found
Against alternating pressure air surfaces, the risk ratio for foam was 1.59 (95% confidence interval 0.86 to 2.95; 4 trials, 2,247 people). Because that range crosses 1, the result could be due to chance. Against reactive air surfaces it was 2.40 (1.04 to 5.54; 4 trials, 229 people) (Shi et al., 2021).
Two single trials suggest some foams may do better than others. Memory foam with a density of 40 to 60 kg per cubic meter may lower the risk compared with 33 kg foam, and solid foam may do better than convoluted, egg-crate style foam. Both findings are low certainty. Alternating pressure air surfaces are probably more cost-effective than foam.
The review was funded by the UK National Institute for Health Research, and the funders had no role in it. An older Cochrane review from 2015 found that higher-specification foam mattresses lowered pressure ulcers compared with standard hospital foam mattresses (risk ratio 0.40) (McInnes et al., 2015).
An earlier version of this page cited a review version and DOI that could not be found, with trial counts and a 60% figure that do not match either review. Those details and the mattress product picks have been removed.
How to Apply This Study When Choosing a Mattress
What it tells you: For people at high risk of bedsores, the type of support surface matters, and air surfaces may do better than standard foam.
If you care for someone who spends most of the day in bed, ask their care team about pressure-relieving surfaces. This review says nothing about which home mattress feels best for healthy sleepers.
Study Scope and Limitations
Most trials were small, 17 of 29 were at high risk of bias, and most findings were low or very low certainty. Participants were mostly older hospital patients. The review did not study healthy people or home mattresses.
Primary Citation
Shi, C., Dumville, J. C., Cullum, N., Rhodes, S., & McInnes, E. (2021). Foam surfaces for preventing pressure ulcers. Cochrane Database of Systematic Reviews, 2021(5), CD013621. https://doi.org/