Gardner 2008.

Methods	Randomised controlled trial (2 arm)
Participants	Inclusioncriteria: patients at risk of pressure injury (Waterlow score > 9) Exclusioncriteria: under 16 years, unable to tolerate extended time lying supine and with sacral pressure injury of Stage 2 or above Number of participants: 66 Age: on average 68 (12.7) years Gender (M:F): 34:25 Baseline skin status: at risk of ulcer (Waterlow score > 9), without existing severe ulcers
Interventions	Airflotation and Ruby mattress Description of interventions: alternating pressure air mattress NPIAP S3I classification: powered, alternating pressure, active, air surface ComfortPlus mattress Description of interventions: unspecified, probably foam surfaces NPIAP S3I classification: non‐powered, reactive, foam surfaces
Outcomes	Outcomes of the interest of this review Unspecified Outcomes unrelated to this review Interface pressure
Notes