Pressure Relieving Support Surfaces: a Randomised Evaluation 2 (PRESSURE 2): using photography for blinded central...

Area of Science:

• Medical device evaluation
• Clinical trial methodology
• Wound care research

Background:

• The PRESSURE 2 trial evaluated mattresses for pressure ulcer (PU) prevention.
• Blinded assessment of PU development is crucial for trial validity but challenging due to mattress visibility.
• Photographic validation was explored to address the need for blinded PU assessment.

Purpose of the Study:

• To validate the use of central blinded photography as a method for assessing pressure ulcers (PUs) in the PRESSURE 2 trial.
• To evaluate the reliability and practical feasibility of using photographs for PU endpoint assessment.
• To address concerns regarding patient consent, data collection burden, and photograph quality.

Main Methods:

• Photographs of skin sites were taken, including those with category ≥2 PUs and a random sample of other sites.
• Standardized procedures, equipment, and training were used for photograph acquisition and transfer.
• Three blinded reviewers assessed photographs, rating their confidence, with a greyscale card used for color correction.

Main Results:

• 85% of 2029 recruited patients consented to photography, with 532 photographs used in blinded review.
• Reliability between photographic assessment and expert clinical assessment was very good (87.8%, kappa 0.82).
• Reviewer confidence varied by skin severity, with higher confidence for less severe classifications.

Conclusions:

• Central blinded photography is a reliable and acceptable method for validating pressure ulcer status in medical device trials.
• This photographic approach helps mitigate bias in clinical evaluations.
• Improvements in photograph quality could further enhance confidence in blinded assessments.