Comparison 1. Constant low‐pressure supports (CLP) vs standard foam mattresses (SFM).

Outcome or subgroup title	No. of studies	No. of participants	Statistical method	Effect size
1 Pressure ulcer incidence	7	2407	Risk Ratio (M‐H, Random, 95% CI)	0.38 [0.24, 0.61]
1.1 Cubed foam mattress	1	36	Risk Ratio (M‐H, Random, 95% CI)	0.34 [0.14, 0.85]
1.2 Bead‐filled mattress	1	75	Risk Ratio (M‐H, Random, 95% CI)	0.32 [0.14, 0.76]
1.3 Softform mattress	1	170	Risk Ratio (M‐H, Random, 95% CI)	0.20 [0.09, 0.45]
1.4 Water‐filled mattress	1	316	Risk Ratio (M‐H, Random, 95% CI)	0.35 [0.15, 0.79]
1.5 Alternative foam	2	644	Risk Ratio (M‐H, Random, 95% CI)	0.36 [0.22, 0.59]
1.6 Hi‐spec foam mattress/cushion	1	1166	Risk Ratio (M‐H, Random, 95% CI)	0.78 [0.55, 1.11]