Using a prognostic medical device for early identification of pressure ulcers: protocol for study design.

Background: An objective, physiological measurement taken using a medical device may reduce the incidence of pressure ulcers through earlier detection of problems signs before visual signs appear. Research in this field is hampered by variations in clinical practice and patient-level confounders.

Aim: The authors outline key considerations for designing a protocol for a study to assess the efficacy and safety of a prognostic medical device in reducing pressure ulcer incidence in a hospital, including comparators, randomisation, sample size, ethics and practical issues.

Method: Key issues relating to methodology and ethics are considered alongside a theoretical protocol, which could support future researchers in wound care trials.

Results: A prospective, three-armed, multi-centre, stratified cluster-randomised controlled trial is proposed. The third arm is recommended as it is expected that patients will need to be moved for the medical device to be used and repositioning is a preventive strategy. A minimum of 16 200 patients in 33 wards would needed to be recruited to achieve statistical significance. Ethical considerations in terms of consent or assent need to be considered.

Conclusion: The hypothetical study designed to evaluate the effectiveness of a diagnostic or prognostic medical device in reducing pressure ulcer incidence in secondary care, while accounting for biases, would require large sample sizes and involves risks of inter-operator and inter-device reliability, heterogeneity of users and the vague clinical interpretation of device results. Robust research in this field has the potential to influence or change policy and practice relating to the prevention of pressure ulcers in secondary care.