Therapies for Inflammatory Bowel Disease Do Not Pose Additional Risks for Adverse Outcomes of SARS-CoV-2 Infection

An IG-IBD Study

Cristina Bezzio; Alessandro Armuzzi; Federica Furfaro; Sandro Ardizzone; Monica Milla; Sonia Carparelli; Ambrogio Orlando; Flavio Andrea Caprioli; Fabiana Castiglione; Chiara Viganò; Davide Giuseppe Ribaldone; Fabiana Zingone; Rita Monterubbianesi; Nicola Imperatore; Stefano Festa; Marco Daperno; Ludovica Scucchi; Antonio Ferronato; Luca Pastorelli; Paola Balestrieri; Chiara Ricci; Maria Cappello; Carla Felice; Gionata Fiorino; Simone Saibeni


Aliment Pharmacol Ther. 2021;54(11_12):1432-1441. 

In This Article


This observational cohort study was supported by the Italian Group for the Study of Inflammatory Bowel Disease (IG-IBD). The primary objective was to identify risk factors for adverse outcomes of COVID-19 in IBD patients. The secondary objective was to develop an index to identify IBD patients at increased risk of severe COVID-19. The study protocol was approved by the IG-IBD Scientific Committee and the Coordinating Ethical Committee of ASST Rhodense. All 96 IBD centres affiliated with IG-IBD were invited to participate in the study.

Patients at participating IBD centres were consecutively included in this study if they had an established diagnosis of Crohn's disease (CD) or UC for at least 6 months and confirmed SARS-CoV-2 infection plus follow-up for at least 1 month. A confirmed SARS-CoV-2 infection was defined as either the polymerase chain reaction-confirmed presence of SARS-CoV-2 genome in a nasopharyngeal swab or the ELISA-confirmed presence of anti-SARS-CoV-2 spike protein antibodies in serum, or both. Data collection was done from March 11 to December 31, 2020.

For all patients, the following data were collected from medical charts and, when possible, patient interviews: age, sex, current smoking habit (yes or no), IBD type, IBD duration, IBD activity (classified as in remission, mild, moderate or severe according to the partial Mayo score for UC[18] and the Harvey-Bradshaw index for CD[19]) in the 3 months before the diagnosis of SARS-CoV-2 infection, IBD treatments, comorbidities (including other concomitant IMIDs), Charlson's comorbidity index (CCI),[20] symptoms of SARS-CoV-2 infection and COVID-19 outcome (favourable, moderate or severe). Symptoms of COVID-19 were classified as: gastrointestinal (diarrhoea, nausea or abdominal pain), systemic (fever, arthralgia, myalgia, asthenia or hyporexia), respiratory (pharyngodynia, cough, rhinitis and dyspnoea) and dysgeusia or anosmia. A moderate COVID-19 outcome was defined as a diagnosis of pneumonia (demonstrated by chest CT or radiography) or the need for hospitalisation, while a severe outcome was defined as ventilatory assistance use (continuous positive airway pressure, non-invasive mechanical ventilation or intubation) or death. These data were entered into an electronic database accessible to participating centres.

Statistical Analysis

Analyses were conducted using SPSS Statistical Software (v. 13.0, IBM). Differences in quantitative variables at baseline between UC and CD patients were tested for significance using the t test. Associations between the type of IBD and categorical variables (baseline characteristics and symptoms of COVID-19) were tested for significance using the chi-square test. A two-tailed P < 0.05 was indicative of statistical significance.

Risk factors for moderate-to-severe COVID-19 outcomes were identified by logistic regression with univariable and multivariable analyses. Multivariable analyses were adjusted for confounding factors that could simultaneously impact upon another variable and the outcome (eg elderly patients are uncommonly prescribed anti-TNF agents, so the use of these drugs was adjusted for age). Confounding factors were selected according to the literature[3–14] and to reports by the Italian national health service on causes of death from COVID-19 in the general population and in IBD patients.[21] The confounding factors selected to adjust the regression analyses were therefore age, comorbidities, IMID and disease activity. Logistic regression was also used to assess the impact of medications on COVID-19 outcomes.

Variables that were retained in the multivariable analyses at P < 0.05 were used to build an index for the risk of moderate-to-severe COVID-19 in IBD patients. The coefficients from the multivariable analysis were used to assess the weight of each variable retained in the model and to calculate the index. We tested the sensitivity, specificity, and positive and negative likelihood ratios of this index using the clinical data from our population. ROC curve analysis was used to set the most sensitive and specific cut-off to identify IBD patients with infection by SARS-CoV-2 at risk of moderate-to-severe COVID-19.