Application of an infrared thermography-based model to detect pressure injuries: a prospective cohort study

Background It is challenging to detect pressure injuries at an early stage of their development. Objectives To assess the ability of an infrared thermography (IRT)-based model, constructed using a convolution neural network, to reliably detect pressure injuries. Methods A prospective cohort study compared validity in patients with pressure injury (n = 58) and without pressure injury (n = 205) using different methods. Each patient was followed up for 10 days. Results The optimal cut-off values of the IRT-based model were 0 center dot 53 for identifying tissue damage 1 day before visual detection of pressure injury and 0 center dot 88 for pressure injury detection on the day visual detection is possible. Kaplan-Meier curves and Cox proportional hazard regression model analysis showed that the risk of pressure injury increased 13-fold 1 day before visual detection with a cut-off value higher than 0 center dot 53 [hazard ratio (HR) 13 center dot 04, 95% confidence interval (CI) 6 center dot 32-26 center dot 91; P < 0 center dot 001]. The ability of the IRT-based model to detect pressure injuries [area under the receiver operating characteristic curve (AUC)(lag 0 days), 0 center dot 98, 95% CI 0 center dot 95-1 center dot 00] was better than that of other methods. Conclusions The IRT-based model is a useful and reliable method for clinical dermatologists and nurses to detect pressure injuries. It can objectively and accurately detect pressure injuries 1 day before visual detection and is therefore able to guide prevention earlier than would otherwise be possible. What is already known about this topic? Detection of pressure injuries at an early stage is challenging. Infrared thermography can be used for the physiological and anatomical evaluation of subcutaneous tissue abnormalities. A convolutional neural network is increasingly used in medical imaging analysis. What does this study add? The optimal cut-off values of the IRT-based model were 0 center dot 53 for identifying tissue damage 1 day before visual detection of pressure injury and 0 center dot 88 for pressure injury detection on the day visual detection is possible. Infrared thermography-based models can be used by clinical dermatologists and nurses to detect pressure injuries at an early stage objectively and accurately.