Keogh 2001.

Methods	RCT with follow‐up of 5‐10 days.
Participants	Patients from 2 surgical and 2 medical wards: > 18 y; Waterlow score of 15‐25; tissue damage no greater than grade 1.
Interventions	1. Profiling bed with a pressure reducing foam mattress/cushion (n = 50). 2. Flat‐based bed with a pressure relieving/redistributing mattress/cushion (n = 50).
Outcomes	Number of pressure ulcers developed: 1. 0/35; 2. 0/35. Healing of existing grade 1 ulcers: 1. 100% (4/4); 2. 20% (2/10).
Notes	Extent of follow‐up difficult to ascertain. No difference between the groups in terms of transferring in and out of bed.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	"The block design randomisation code was computer generated by an independent statistician using blocks of eight".
Allocation concealment (selection bias)	Low risk	"The allocation for each patient was placed in sealed opaque envelopes that were numbered sequentially. The patient and researcher were not aware of allocation until after recruitment".
Blinding (performance bias and detection bias) Pressure ulcer incidence	Unclear risk	Pressure ulcer incidence.
Incomplete outcome data (attrition bias) All outcomes	High risk	"A total of 100 patients were recruited into the study. Data were incomplete for 30 of these patients. All 100 patients were included in an intention‐to‐treat analysis in respect of pressure ulcer incidence".
Selective reporting (reporting bias)	Low risk	All pre‐specified outcomes reported.
Free of other bias ‐ were groups similar at baseline regarding the most important prognostic indicators?	Low risk	Imbalance in male to female ratio (M:F 20:30 in control and 35:15 in treatment). Balanced on initial nutritional assessment score BMI, age, mobility score.
Free of other bias ‐ was the timing of the outcome assessment similar in all groups?	Low risk	"Waterlow scores were assessed and pressure areas observed daily".