P151 Validation of the Inflammatory Bowel Disease Disability Index in a population-based cohort
C. Gower-Rousseau*1, H. Sarter1, N. Tavernier2, G. Savoye3, M. Fumery4, A. Duhamel5, N. Guillon-Dellac1, A. Cieza6, J.-F. Colombel7, L. Peyrin-Biroulet8
1Lille University Hospital, Epidemiology, Lille, France, 2Lille University Hospital, Gastroenterology, Lille, France, 3Rouen University Hospital, Gastroenterology, Rouen, France, 4Amiens University Hospital, Gastroenterology, Amiens, France, 5Lille University Hospital , Biostatistics, Lille, France, 6University of Southampton, Faculty of Social and Human Sciences, Southampton, United Kingdom, 7Icahn School of Medicine at Mount Sinai, Department of Medicine, New York City, United States, 8Nancy University Hospital , Gastroenterology , Nancy, France
Inflammatory bowel diseases (IBD) are chronic disabling conditions influencing physical, psychological, familial and social dimensions of life and may result in disability. Recently, an international collaborative effort led to the development of the first IBD Disability Index (IBD-DI) according to the WHO classification (1). The aims of this prospective study were: 1. To validate the IBD-DI in an independent cohort of IBD patients; 2. To develop a scoring system for the IBD-DI to be used in clinical trials and cohort studies; 3. To assess for the first time disability status among a well-defined population-based cohort of French IBD patients using the IBD-DI and to identify associated factors.
From February 1st 2012 to 31st March 2014, the questionnaire was administered to a random sample of 200 adult patients with an established diagnosis of IBD for at least 3 months. This random sample was selected among a well-defined population-based registry in France. The IBD-DI consists of 28 items covering the 4 domains of Body Functions, Activity Participation, Body Structures and Environmental Factors. The steps of the quantitative validation included Item quality, factorial validity, internal and external consistency, inter and intra-observer reproducibility. Socio demographic and clinical associated factors were assessed using a multivariate regression. Clinical variables according to the Montreal classification and disease activity according to HBI and partial Mayo scores were recorded at the time of interview.
A total of 150 CD and 50 UC patients completed the validation phase of the IBD-DI. Intraclass correlation was 0.9 and Cronbach's alpha of internal consistency was 0.86. IBD-DI correlated with IBDQ (-0.82; p<10-3) and SF36 (-0.61 for physical and -0.71 for Mental; p<0.05). IBD-DI score varied from 0 to 100 (higher is the IBD-DI higher is the disability) with a mean at 35.3 ± 20.5 without any difference between CD and UC (33.9 ± 19.5 in CD vs 39.2 ± 23.1 in UC; p=0.12). The only factor independently associated with higher IBD-DI in both CD and UC was the female gender. The IBD-DI was associated with increased clinical disease activity (p<10-4) in CD, while a trend was observed in UC (p=0.06).
The IBD-DI is reliable and reproducible for measuring disability status in IBD. It comprises 19 questions and it ranges from 0 to 100. The mean disability score was 35, it correlated with clinical disease activity and was associated with female gender in this population-based cohort. This validated index and its scoring system can now be used in cohort studies and clinical trials.
(1) Peyrin-Biroulet et al. Gut 2012;61:241-7