Interobserver reliability of the Nancy index for ulcerative colitis: An assessment of the practicability and ease of use in a single-centre real-world setting.

The NI is an easy-to-use index with high interobserver reliability to assess the histological disease activity of UC patients in a real-world setting. While NI grades 0 and 3 had a high level of agreement between the observers, NI grade 1 had a poorer agreement-level. This highlights the clinical need to specify histological characteristics leading to NI grade 1.