Randomised, controlled trial of alternating pressure mattresses compared with alternating pressure overlays for the prevention of pressure ulcers: PRESSURE (pressure relieving support surfaces) trial

Abstract

Objective: To compare whether differences exist between alternating pressure overlays and alternating pressure mattresses in the development of new pressure ulcers, healing of existing pressure ulcers, and patient acceptability. Design: Pragmatic, open, multicentre, randomised controlled trial. Setting: 11 hospitals in six NHS trusts. Participants: 1972 people admitted to hospital as acute or elective patients. Interventions: Participants were randomised to an alternating pressure mattress (n = 982) or an alternating pressure overlay (n = 990). Main outcome measures: The proportion of participants developing a new pressure ulcer of grade 2 or worse; time to development of new pressure ulcers; proportions of participants developing a new ulcer within 30 days; healing of existing pressure ulcers; and patient acceptability. Results: Intention to treat analysis found no difference in the proportions of participants developing a new pressure ulcer of grade 2 or worse (10.7% overlay patients, 10.3% mattress patients; difference 0.4%, 95% confidence interval -2.3% to 3.1%, P = 0.75). More overlay patients requested change owing to dissatisfaction (23.3%) than mattress patients (18.9%, P = 0.02). Conclusion: No difference was found between alternating pressure mattresses and alternating pressure overlays in the proportion of people who develop a pressure ulcer.