Incontinence-associated dermatitis (IAD) is a specific type of irritant contact dermatitis 3 with different levels of severity. An internationally accepted instrument to assess the severity of IAD in adults with established diagnostic accuracy, agreement, and reliability is needed to support clinical practice and research. The objective of the presentation is to discuss the design and psychometric evaluation the Ghent Global IAD Categorisation Tool (GLOBIAD).The design was based on expert consultation using a three-round Delphi procedure with 34 experts from 13 countries. The instrument was tested using IAD photographs reflecting different severity levels in a sample of 823 health professionals in 30 countries. Measures for diagnostic accuracy (sensitivity and specificity), agreement, inter- rater reliability (multi- rater Fleiss kappa), and intra- rater reliability (Cohen’s Kappa) were assessed The GLOBIAD consists of two categories according to the presence of persistent redness (Cat.1) and skin loss (Cat.2), both subdivided based on the presence of clinical signs of infection. The agreement for differentiating between Cat.1 and Cat.2 was 0.86 [95% confidence interval (CI) 0.86-0.87], with a sensitivity of 90% and a specificity of 84%. The overall agreement was 0.55 (95%CI, 0.55-0.56). The Fleiss Kappa for differentiating between Cat.1 and Cat.2 was 0.65 (95%CI 0.65-0.65).The overall Fleiss Kappa was 0.41 (95%CI 0.41-0.41). The Cohen’s Kappa for differentiating between Cat.1 and Cat.2 was 0.76 (95%CI 0.75-0.77). The overall Cohen’s Kappa was 0.61 (95%CI 0.59-0.62). The development of the GLOBIAD is a major step forward towards a better systematic assessment of IAD in clinical practice and research worldwide. Further validation is however needed.