Development and validation of a new disease severity index: the Inflammatory Bowel Disease Index (IBDEX)

• Published in: Frontline gastroenterology 2015-07, Vol.6 (3), p.161-168
• Main Authors: Alrubaiy, Laith, Dodds, Phedra, Hutchings, Hayley Anne, Russell, Ian Trevor, Watkins, Alan, Williams, John Gordon
• Format: Article
• Language: English
• Subjects: Clinical medicine; Clinical trials; Colorectal; Endoscopy; Gastroenterology; Inflammation; Inflammatory bowel disease; Laboratories; Principal components analysis; Quantitative psychology; Validation studies
• ISSN: 2041-4137; 2041-4145
• DOI: 10.1136/flgastro-2014-100530

ObjectiveTo develop, validate and apply a generic clinical severity index applicable to all adult patients with inflammatory bowel disease (IBD).DesignA review of the literature and an expert focus group consultation were carried out in order to draw out relevant items from existing literature. The new index was called the IBD Index (IBDEX). Standard psychometric analysis was carried out. The construct validity was assessed against biochemical markers, clinical and endoscopic indices. The new index was completed again within 6 weeks to check responsiveness and reproducibility.ResultsIBDEX was used to assess 255 adult patients with IBD (125 with Crohn’s disease and 130 with ulcerative colitis), and 64 patients were re-evaluated within 6 weeks. It had good internal consistency (Cronbach's α=0.79) and correlated very well with the Harvey Bradshaw Index (r=0.94), the Simple Clinical Colitis Activity Index (r=0.92), the Mayo Clinic Index (r=0.87) and the Simple Endoscopic Score (r=0.76), all with p values