Ref (type)	Population	Outcome, Interventions	Results and statistical analysis	Effect size	Favours
Healing rates
Systematic review	199 people, 158 people completed study, mean age 80 years, acute care, grade I to IV ulcers Data from 1 RCT	Wound surface area ulcer progress 72% with alternating-pressure mattress 75% with fluid mattress overlay Absolute numbers not reported	P = 0.76		Not significant
Systematic review	113 people completed study, 55 years or over, acute care, grade II ulcers Data from 1 RCT	Complete wound healing 10.3% with one type of alternating-pressure mattress 10.7% with another type of alternating-pressure overlay Absolute numbers not reported	P = 0.75		Not significant
Systematic review	32 people completed study, aged 65 years or over, acute and long-term care, grade II or III ulcers Data from 1 RCT	Reduction in median wound surface area per day 0.12 cm with one type of alternating-pressure mattress 0.08 cm with another type of alternating-pressure mattress	P = 0.57		Not significant
Systematic review	17 people, age range 66 to 99 years, acute and long-term care, grade II to IV ulcers Data from 1 RCT	Wound surface area with one type of alternating-pressure mattress with another type of alternating-pressure mattress or overlay Absolute results not reported	Reported as no significant difference in healing sores P value not reported		Not significant
Systematic review	183 people, 112 completed study, age described as elderly, acute care, grade II to IV ulcers	Complete heel ulcer healing with one type of alternating-pressure mattress plus cushion with another type of alternating-pressure mattress plus cushion Absolute results not reported	P = 0.02	Effect size not calculated	alternating-pressure mattress plus cushion