. 2021 Aug 16;2021(8):CD013761. doi: 10.1002/14651858.CD013761.pub2

2. Prevention network: summary of findings for key comparisons with foam surfaces as the reference.

Outcome: pressure ulcer incidence
Patient or population: people at risk of having pressure ulcers Setting: any care settings Intervention: reactive air surfaces; alternating pressure (active) air surfaces; reactive gel surfaces; reactive sheepskin surfaces; reactive fibre surfaces; reactive water surfaces; reactive gel surfaces followed by foam surfaces Comparator (reference): foam surfaces Follow‐up durations: median 14 days (range: 3 days to 12 months)
Total studies: 40 RCTs Total participants: 12,517	Anticipated absolute effects^* (95% CI)			Relative effect from network meta‐analysis (95% CI)	Certainty of the evidence (GRADE)	Surface Under the Cumulative RAnking (SUCRA)	Comments
Interventions (numbers of studies and participants comparing the named intervention with foam surfaces)	Risk with foam surfaces	Risk with a type of support surface	Difference	Relative effect from network meta‐analysis (95% CI)	Certainty of the evidence (GRADE)	Surface Under the Cumulative RAnking (SUCRA)	Comments
Reactive air surfaces (4 RCTs, 229 participants)	106 per 1000	49 per 1000 (31 to 80)	57 fewer per 1000 (26 fewer to 75 fewer)	RR 0.46 (0.29 to 0.75)	⨁⨁◯◯ LOW^a,b	78.1% ⨁◯◯◯ VERY LOW^a,b,c	Reactive air surfaces may reduce pressure ulcer incidence compared with foam surfaces. It is uncertain how likely it is that reactive air surfaces are the best intervention in reducing pressure ulcer incidence.
Alternating pressure (active) air surfaces (4 RCTs, 2247 participants)	106 per 1000	67 per 1000 (44 to 98)	39 fewer per 1000 (8 fewer to 62 fewer)	RR 0.63 (0.42 to 0.93)	⨁⨁◯◯ LOW^a,b	59.3% ⨁◯◯◯ VERY LOW^a,b,c	Alternating pressure (active) air surfaces may reduce pressure ulcer incidence compared with foam surfaces. It is uncertain how likely it is that alternating pressure (active) air surfaces are the best intervention in reducing pressure ulcer incidence.
Reactive gel surfaces (no analysable data for this direct comparison)	106 per 1000	51 per 1000 (23 to 108)	56 fewer per 1000 (83 fewer to 1 more)	RR 0.47 (0.22 to 1.01)	⨁⨁◯◯ LOW^c	74.6% ⨁◯◯◯ VERY LOW^a,b,c	Reactive gel surfaces may reduce pressure ulcer incidence compared with foam surfaces. It is uncertain how likely it is that reactive gel surfaces are the best intervention in reducing pressure ulcer incidence.
Reactive sheepskin surfaces (no analysable data for this direct comparison)	106 per 1000	61 per 1000 (34 to 111)	45 fewer per 1000 (72 fewer to 5 more)	RR 0.58 (0.32 to 1.05)	⨁◯◯◯ VERY LOW^c,d	64.1% ⨁◯◯◯ VERY LOW^a,b,c	It is uncertain if there is a difference between reactive sheepskin surfaces and foam surfaces in reducing pressure ulcer risk. It is uncertain how likely it is that reactive sheepskin surfaces are the best intervention in reducing pressure ulcer incidence.
Reactive fibre surfaces (1 RCT, 68 participants)	106 per 1000	75 per 1000 (40 to 142)	31 fewer per 1000 (66 fewer to 36 more)	RR 0.71 (0.38 to 1.34)	⨁◯◯◯ VERY LOW^c,d	50.6% ⨁◯◯◯ VERY LOW^a,b,c	It is uncertain if there is a difference between reactive fibre surfaces and foam surfaces in reducing pressure ulcer risk. It is uncertain how likely it is that reactive fibre surfaces are the best intervention in reducing pressure ulcer incidence.
Reactive water surfaces (no analysable data for this direct comparison)	106 per 1000	46 per 1000 (18 to 115)	60 fewer per 1000 (88 fewer to 9 fewer)	RR 0.43 (0.17 to 1.09)	⨁◯◯◯ VERY LOW^c,d	77.7% ⨁◯◯◯ VERY LOW^a,b,c	It is uncertain if there is a difference between reactive water surfaces and foam surfaces in reducing pressure ulcer risk. It is uncertain how likely it is that reactive water surfaces are the best intervention in reducing pressure ulcer incidence.
Reactive gel surfaces followed by foam surfaces (no analysable data for this direct comparison)	106 per 1000	305 per 1000 (74 to 1000)	199 more per 1000 (32 fewer to 894 more)	RR 2.88 (0.70 to 11.83)	⨁◯◯◯ VERY LOW^a,c	7.6% ⨁◯◯◯ VERY LOW^a,b,c	It is uncertain if there is a difference between reactive gel surfaces followed by foam surfaces and foam surfaces in reducing pressure ulcer risk. It is uncertain how likely it is that reactive gel surfaces followed by foam surfaces are the best intervention in reducing pressure ulcer incidence.
*The risk in the intervention group (and its 95% confidence interval) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI).  CI: confidence interval; RR: risk ratio
GRADE Working Group grades of evidence High certainty: we are very confident that the true effect lies close to that of the estimate of the effect. Moderate certainty: we are moderately confident in the effect estimate. The true effect is likely to be close to the estimate of the effect, but there is a possibility that it is substantially different. Low certainty: our confidence in the effect estimate is limited. The true effect may be substantially different from the estimate of the effect. Very low certainty: we have very little confidence in the effect estimate. The true effect is likely to be substantially different from the estimate of effect.

^aDowngraded once for some concerns about within‐study bias (risk of bias). ^bDowngraded once for heterogeneity. ^cDowngraded twice for imprecision. ^dDowngraded twice for risk of bias.