Abstract: International Journal of Antimicrobial Agents 57 (2021) 106249 Contents lists available at ScienceDirect International Journal of Antimicrobial Agents journal homepage: www.elsevier.com/locate/ijantimicag COVID-19 in hospitalised patients in Spain: a cohort study in Madrid Carmen Guadalupe Rodriguez-Gonzalez a,b,∗, Esther Chamorro-de-Vega a,b, Maricela Valerio b,c, Miguel Angel Amor-Garcia a,b, Francisco Tejerina b,c, Milagros Sancho-Gonzalez b,d, Alvaro Narrillos-Moraza a,b, Alvaro Gimenez-Manzorro a,b, Silvia Manrique-Rodriguez a,b, Marina Machado b,c, Maria Olmedo b,c, Vicente Escudero-Vilaplana a,b, Cristina Villanueva-Bueno a,b, Beatriz Torroba-Sanz a,b, Alejandra Melgarejo-Ortuño a,b, Juan Vicente-Valor a,b, Ana Herranz a,b, Emilio Bouza b,c,e,f, Patricia Muñoz b,c,e,f, Maria Sanjurjo a,b a Pharmacy Department, Hospital General Universitario Gregorio Marañón, Madrid, Spain Instituto de Investigación Sanitaria Gregorio Marañón, Madrid, Spain c Clinical Microbiology and Infectious Diseases Department, Hospital General Universitario Gregorio Marañón, Madrid, Spain d Intensive Care Department, Hospital General Universitario Gregorio Marañón, Madrid, Spain e CIBERES, CIBER Enfermedades Respiratorias, Madrid, Spain f Departamento de Medicina, Facultad de Medicina, Universidad Complutense de Madrid, Spain b a r t i c l e i n f o Article history: Received 16 July 2020 Accepted 22 November 2020 Editor: Professor Jeffrey Lipman Keywords: SARS-CoV-2 COVID-19 Risk factors Mortality Costs Spain a b s t r a c t Few large series describe the clinical characteristics, outcomes and costs of COVID-19 in Western countries. This cohort reports the first 1255 adult cases receiving anti-COVID-19 treatment at a Spanish hospital (1–24 March 2020). Treatment costs were calculated. A logistic regression model was used to explore risk factors on admission associated with ARDS. A bivariate Cox proportional hazard ratio (HR) model was employed to determine the HR between individual factors and death. We included 1255 patients (median age 65 years; 57.8% male), of which 92.3% required hospitalisation. The prevalence of hypertension, cardiovascular disease and diabetes mellitus (DM) was 45.1%, 31.4% and 19.9%, respectively. Lymphocytopenia (54.8%), elevated alanine aminotransferase (33.0%) and elevated lactate dehydrogenase (58.5%) were frequent. Overall, 36.7% of patients developed ARDS, 10.0% were admitted to an ICU and 21.3% died. The most frequent antiviral combinations were lopinavir/ritonavir plus hydroxychloroquine (44.2%), followed by triple therapy with interferon beta-1b (32.7%). Corticosteroids and tocilizumab were used in 25.3% and 12.9% of patients, respectively. Total cost of anti-COVID-19 agents was €511 825 (€408/patient). By multivariate analysis, risk factors associated with ARDS included older age, obesity, DM, severe hypoxaemia, lymphocytopenia, increased creatine kinase and increased C-reactive protein. In multivariate Cox model, older age (HR 1.07, 95% CI 1.06–1.09), cardiovascular disease (HR 1.34, 95% CI 1.01–1.79), DM (HR 1.45, 95% CI 1.09–1.92), severe hypoxaemia (HR 2.01, 95% CI 1.49–2.72), lymphocytopenia (HR 1.62, 95% CI 1.20–2.20) and increased C-reactive protein (HR 1.04, 95% CI 1.02–1.06) were risk factors for mortality. © 2020 Published by Elsevier Ltd.