PT - JOURNAL ARTICLE AU - Bilal Akhter Mateen AU - Sandip Samanta AU - Sebastian Tullie AU - Sarah O’Neill AU - Zillah Cargill AU - Gillian Kelly AU - Ewen Brennan AU - Mehul Patel AU - Mohammad Al-Agil AU - James Galloway AU - James Teo AU - Debbie L Shawcross AU - Alexandra J Kent AU - Bu'Hussain Hayee TI - Diarrhoea and preadmission antibiotic exposure in COVID-19: a retrospective cohort study of 1153 hospitalised patients AID - 10.1136/bmjgast-2020-000593 DP - 2021 Sep 01 TA - BMJ Open Gastroenterology PG - e000593 VI - 8 IP - 1 4099 - http://bmjopengastro.bmj.com//content/8/1/e000593.short 4100 - http://bmjopengastro.bmj.com//content/8/1/e000593.full SO - BMJ Open Gastro2021 Sep 01; 8 AB - Objective The aims of this study were to describe community antibiotic prescribing patterns in individuals hospitalised with COVID-19, and to determine the association between experiencing diarrhoea, stratified by preadmission exposure to antibiotics, and mortality risk in this cohort.Design/methods Retrospective study of the index presentations of 1153 adult patients with COVID-19, admitted between 1 March 2020 and 29 June 2020 in a South London NHS Trust. Data on patients’ medical history (presence of diarrhoea, antibiotic use in the previous 14 days, comorbidities); demographics (age, ethnicity, and body mass index); and blood test results were extracted. Time to event modelling was used to determine the risk of mortality for patients with diarrhoea and/or exposure to antibiotics.Results 19.2% of the cohort reported diarrhoea on presentation; these patients tended to be younger, and were less likely to have recent exposure to antibiotics (unadjusted OR 0.64, 95% CI 0.42 to 0.97). 19.1% of the cohort had a course of antibiotics in the 2 weeks preceding admission; this was associated with dementia (unadjusted OR 2.92, 95% CI 1.14 to 7.49). After adjusting for confounders, neither diarrhoea nor recent antibiotic exposure was associated with increased mortality risk. However, the absence of diarrhoea in the presence of recent antibiotic exposure was associated with a 30% increased risk of mortality.Conclusion Community antibiotic use in patients with COVID-19, prior to hospitalisation, is relatively common, and absence of diarrhoea in antibiotic-exposed patients may be associated with increased risk of mortality. However, it is unclear whether this represents a causal physiological relationship or residual confounding.Data are available upon reasonable request. Data cannot be shared publicly due to restrictions associated with access granted to routinely collected information in the absence of informed consent. Requests for access to the data extract used for this study should be directed to kch-tr.cogstackrequests@nhs.net.