Gray 2008.

Study characteristics
Methods	Study objective: to determine the effect of using the Softform Premier Active™ Mattress versus a standard air mattress on pressure ulcer incidence in 2 acute care of the elderly wards Study design: randomised controlled trial Study grouping: parallel group Duration of follow‐up: not given (claimed this is a 6 month study) Number of arms: 2 Single centre or multi‐site: 2 acute wards Study start date and end date: not described Setting: acute care of the elderly wards
Participants	Baseline characteristics Inclusion criteria: patients considered to be at high risk of pressure ulcer development Exclusion criteria: not given Sex (M:F): not given Age (years): mean 82.4 in Softform Premier Active mattress; 84.0 in standard air mattress Baseline skin status: mean Waterlow risk score 22.2 (range 17 to 29) in Softform Premier Active mattress; 21.6 (range 17 to 29) in standard air mattress Group difference: no difference Total number of participants: n = 100 Unit of analysis: individuals Unit of randomisation (per patient): individuals
Interventions	Intervention characteristics Softform Premier Active Mattress Description of interventions: Softform Premier Active Mattress consisting of a Softform Premier foam mattress with a dynamic underlay. The underlay alternates on a 10‐minute cycle, and can be activated through connection to a portable pump ... to create an alternating surface for use in patients at very high risk of pressure ulcer development. When the alternating surface is not required, the pump can be disconnected, and the mattress becomes static ... The ability to use the mattress as either a dynamic or static surface ... allowing their care to be stepped up or down as appropriate. NPUAP S3I classification: powered, alternating pressure (active) air surface; hybrid (active and reactive modes) mattress Co‐interventions: Softform Active mattresses and pressure‐reducing cushions (Softform Premier Active Cushions; Invacare, Cardiff) used by all participants if required Number of participants randomised: not described Number of participants analysed: n = 50 Standard air mattress Description of interventions: standard alternating pressure air mattress NPUAP S3I classification: powered, alternating pressure (active) air surface Co‐interventions: Softform Active mattresses and pressure‐reducing cushions (Softform Premier Active Cushions; Invacare, Cardiff) used by all participants if required Number of participants randomised: not described Number of participants analysed: n = 50
Outcomes	Proportion of participants developing a new pressure ulcer Outcome type: binary Time points: 6 months Reporting: partially reported Measurement method (e.g. scale, self‐reporting): EPUAP 2001 Definition (including ulcer stage): grade 2 ulcer incidence Dropouts: not described Notes (e.g. other results reported): 4 of 50 patients using Softform Premier Active Mattress developed superficial, grade 2 ulcers; 4 of 50 in standard air mattress Time to pressure ulcer development Not reported Support‐surface‐associated patient comfort Not reported All reported adverse events using allocated support surfaces Not reported Health‐related quality of life (HRQOL) Not reported Cost‐effectiveness Not reported Outcomes that are not considered in this review but reported in trials: Patient acceptability rated by staff nurses
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Quote: "Patients considered to be at high risk of pressure ulcer development were randomly allocated to a Softform Premier Active or standard air mattress" Comment: unclear risk of bias because the sequence generation process is not described.
Allocation concealment (selection bias)	Unclear risk	Comment: no information provided.
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	Comment: no information provided.
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Outcome group: ulcer incidence Quote: "Any pressure ulcers that developed during the study period were graded by a member of the tissue viability department." Comment: unclear risk of bias because blinding of outcome assessment is not described.
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	Outcome group: ulcer incidence Comment: unclear risk of bias because the numbers randomised to arms are not detailed.
Selective reporting (reporting bias)	Low risk	Comment: the study protocol is not available but it is clear that the published reports include all expected outcomes, including those that were pre‐specified.
Other bias	Low risk	Comment: the study appears to be free of other sources of bias.