key: cord-1015892-qpm3d4h9 authors: Hadi, Yousaf; Kochhar, Gursimran S. title: Letter: association between COVID‐19 and inflammatory bowel disease—Authors' reply date: 2022-04-16 journal: Aliment Pharmacol Ther DOI: 10.1111/apt.16900 sha: d1aca3373f40595001a7e90746dedfa3141fb195 doc_id: 1015892 cord_uid: qpm3d4h9 This article is linked to Hadi et al papers. To view these articles, visit https://doi.org/10.1111/apt.16730 and https://doi.org/10.1111/apt.16814 for IBD, many published database studies rely on ICD codes alone for identification of IBD cohorts; and strategies involving only ICD diagnosis codes have achieved >90% positive predictive value in identifying IBD cohorts. 3, 4 In order to achieve sufficient confidence in our cohort, in addition to ICD diagnosis codes, we included the presence of IBD medications in our definition, thus making the criteria more stringent. We opted against further addition of endoscopy procedures as not all IBD patients undergo endoscopy when hospitalised. Our data and analysis spanned the earlier phase of the pan- In regard to antibiotics, the rates of azithromycin administration, which was used for treatment in COVID-19 disease early in the pandemic, were similar in the two cohorts in our analysis; any difference in antibiotics used for other diseases in the cohorts cannot be ruled out. However, it can be postulated that the rate of antibiotic usage should be higher in the COVID-19 cohort, as they may suffer from nosocomial and other infections. However, due to lack of any increased risk of de novo IBD observed in our analysis, the potential of any confounding by antibiotic usage seems to be of minor significance to the conclusion. This would have represented a limitation if a positive effect of COVID-19 on de novo IBD had been noted. The selection criteria codes used in the study: The author's declaration of personal and funding interests are unchanged from those from the original article. 2 Letter: association between COVID-19 and inflammatory bowel disease Incidence, outcomes, and impact of COVID-19 on inflammatory bowel disease: propensity matched research network analysis Validating inflammatory bowel disease (IBD) in the Swedish National Patient Register and the Swedish quality register for IBD (SWIBREG) Incidence and treatment of patients diagnosed with inflammatory bowel diseases at 60 years or older in Sweden COVID-19 vaccinations in patients with inflammatory bowel disease Humoral immune response to messenger RNA COVID-19 vaccines among patients with inflammatory bowel disease 2021