Development and validation of a web-based questionnaire to identify environmental risk factors for inflammatory bowel disease: the Groningen IBD Environmental Questionnaire (GIEQ)

Kimberley Wilhelmina Johanna Van Der Sloot,Behrooz Zaid Alizadeh,Gerard Dijkstra,Rinse Karel Weersma

doi:10.1007/s00535-018-1501-z

Kimberley Wilhelmina Johanna Van Der Sloot, Behrooz Zaid Alizadeh + Show 2 more

Open Access

https://doi.org/10.1007/s00535-018-1501-z

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Abstract

BackgroundIn the complex etiology of inflammatory bowel disease (IBD), the exposome is a major contributor. Though many environmental exposures have been identified, quality of evidence varies greatly and overall evidence for the exposome is inconclusive. A universal, precise, and reproducible measurement tool is needed to study the exposome in IBD.MethodsWe built the web-based Groningen IBD Environmental Questionnaire (GIEQ), an extensive and structured questionnaire measuring potentially involved environmental exposures, consisting of 848 items, subdivided into 15 categories. For validation, 76 IBD patients completed the GIEQ twice (2-month interval). Cohen’s kappa and correlation coefficients were used to compare both fills. Internal consistency was evaluated using Cronbach’s alpha tests. Proportional bias was examined using Bland–Altman plots.ResultsIn general, we obtained a mean kappa coefficient of 0.78 (standard deviation 0.17) for categorical questions and a mean intraclass correlation coefficient of 0.88 (0.15) for numeric questions. Cronbach’s alpha ranged from 0.64 to 1.0 with a mean of 0.79 (0.14). Bland–Altman plots showed proportional bias only for current physical activity score.ConclusionsThe GIEQ is a reliable measurement tool to study the exposome in IBD, enabling consistent measurement of an extended number of environmental factors and their interactions. Use of the GIEQ across IBD cohorts will lead to more standardized, generalizable, and comparable results. Also, the GIEQ can be used for calculation of an exposome risk score, applicable for secondary prevention by identifying high-risk patients as well as to analyze interactions between the exposome and other aspects of IBD etiology.

Highlights

Inflammatory bowel disease (IBD), consisting of ulcerative colitis (UC) and Crohn’s disease (CD), is a gastrointestinal disease characterized by chronic inflammation [1]
To build a reliable and reproducible measurement tool to study the exposome in inflammatory bowel disease (IBD), a number of consecutive steps have been followed, which will be discussed in chronological order (Fig. 2)
Universal measurement tool to evaluate the exposome in patients with IBD

Summary

Introduction

Inflammatory bowel disease (IBD), consisting of ulcerative colitis (UC) and Crohn’s disease (CD), is a gastrointestinal disease characterized by chronic inflammation [1]. Other environmental exposures come into play, e.g., the use of hormone-containing medications and non-steroidal anti-inflammatory drugs (NSAIDs), increasing chances of developing IBD [15,16,17]. Exposures concerning living environment seem to play a role in disease development regardless of time of exposure, such as living in southern latitudes as shown by a Scandinavian study, a high summer temperature, and an increased concentration of (predicted) vitamin D, all thought to play a protective role against development of IBD, opposite to the potential role of air pollution [20,21,22]. In the complex etiology of inflammatory bowel disease (IBD), the exposome is a major contributor. A universal, precise, and reproducible measurement tool is needed to study the exposome in IBD

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