Defining and measuring disease burden in Crohn’s disease: a systematic literature review

OBJECTIVES: Crohn's disease (CD) is a chronic, progressive inflammatory bowel disease with evolving disease behaviour, cumulative bowel damage, and long-term impact on patients and health systems. While treat-to-target strategies focus on inflammatory control, disease burden extends beyond active inflammation to include functional, psychosocial, and economic effects. This review aimed to synthesise how disease burden in CD is defined and measured across the literature. METHODS: A systematic literature review and narrative synthesis were conducted (PROSPERO protocol CRD420251182987). MEDLINE, EMBASE, CINAHL, and PsycINFO were searched on 3 November 2025 for primary studies involving adults with CD that referenced disease burden. Screening and data extraction were performed in duplicate. Study quality was appraised using Joanna Briggs Institute (JBI) tools and considered during narrative synthesis. RESULTS: Twenty-eight studies from diverse regions and study designs were included. Disease burden was variably defined, encompassing clinical activity, cumulative complications, patient-reported symptoms, functional and societal impact, healthcare utilisation, and population-level epidemiology. Measures clustered into five domains: disease activity and inflammation, patient-reported burden, functional and societal impact, healthcare utilisation and treatment burden, and population-level burden. These domains were typically assessed in isolation, and no study integrated objective clinical measures with patient-reported or quality-of-life outcomes. CONCLUSIONS: Disease burden in Crohn's disease is inconsistently defined and measured, reflecting its multidimensional nature but highlighting the absence of an integrated framework. Development of longitudinal, multidimensional tools combining biological, patient-reported, functional, and economic measures is needed to better capture disease burden and support holistic clinical care.