key: cord-0831193-iqb9tjrj
authors: Gower-Rousseau, C.; Fumery, M.; Pariente, B.
title: Inflammatory bowel disease and the SARS-CoV-2 pandemic: more speed, less haste
date: 2020-05-08
journal: Gastroenterology
DOI: 10.1053/j.gastro.2020.05.013
sha: 84f4a888b6ae06cae7cf8c8e1e664a2a3f01ff63
doc_id: 831193
cord_uid: iqb9tjrj

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The provision of well-grounded answers to the above-mentioned questions requires complex epidemiological risk/benefit analyses with an a priori sample size calculation and a design that takes account of confounding factors and likely sources of bias (3). According to modelling results recently published by the Institut Pasteur (Paris, France), only 6% of the French population may have been in contact with SARS-CoV-2, and 2.6% of exposed people have been hospitalized for COVID-19 (4).

Given the lack of solid epidemiological evidence, we referred to our population-based registry (EPIMAD) of all incident cases of IBD recorded in northern France since 1988 (5) . This area has around 6 million inhabitants, i.e. around 10% of the whole French population. We calculate that at the time of writing, around 20 patients with IBD should have been hospitalized for COVID-19 in northern France. We also hypothesize that a lower than expected number of severe cases of COVID-19 might be primarily due to tighter containment of people suffering from chronic diseases.

This low expected number of incident cases of COVID-19 among patients with IBD prevents any analysis of factors associated with severe viral disease. Our calculation highlights how difficult is it to build rigorous, robust studies designed to answer crucial questions about managing patients with chronic diseases during the SARS-CoV-2 pandemic.

The recently published, underpowered publications cannot provide answers for IBD patients, and more generally infrequent diseases, and may even prompt misguided and possibly harmful treatment decisions.

Word count: 424

Modern Epidemiology