HARTI Global Study • OFID • 1 Open Forum Infectious Diseases MAJOR ARTICLE Received 1 June 2021; editorial decision 22 September 2021; accepted 29 September 2021; published online 5 October 2021. Correspondence: G. Ispas, PhD, 2340, Turnhoutseweg 30, 2340 Beerse, Belgium (gispas@ its.jnj.com). Open Forum Infectious Diseases ® 2021 © The Author(s) 2021. Published by Oxford University Press on behalf of Infectious Diseases Society of America. This is an Open Access article distributed under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs licence (https://creativecommons.org/licenses/ by-nc-nd/4.0/), which permits non-commercial reproduction and distribution of the work, in any medium, provided the original work is not altered or transformed in any way, and that the work is properly cited. For commercial re-use, please contact journals.permissions@oup.com https://doi.org/10.1093/ofd/ofab491 Risk Factors and Medical Resource Utilization of Respiratory Syncytial Virus, Human Metapneumovirus, and Infuenza-Related Hospitalizations in Adults—A Global Study During the 2017–2019 Epidemic Seasons (Hospitalized Acute Respiratory Tract Infection [HARTI] Study) Ann R. Falsey, 1 Edward E. Walsh, 1 Stacey House, 2 Yannick Vandenijck, 3 Xiaohui Ren, 3 Sofa Keim, 3 Diye Kang, 3 Pascale Peeters, 4 James Witek, 5 and Gabriela Ispas 3 1 University of Rochester School of Medicine and Rochester Regional Health, Rochester, New York, USA, 2 Washington University School of Medicine, St Louis, Missouri, USA, 3 Janssen Infectious Diseases, Beerse, Belgium, 4 IQVIA Real-World Solutions, Courbevoie, France, and 5 Janssen Research & Development, LLC, Titusville, New Jersey, USA Background. Respiratory syncytial virus (RSV), human metapneumovirus (hMPV), and infuenza are respiratory pathogens leading to hospitalization in adults. Our understanding of the disease burden is limited to data from single-center or 1-season studies in elderly patients. Te HARTI study allows comparison of risk factors for progression to severe disease and medical resources utili- zation (MRU) during and post-hospitalization in adults diagnosed with infuenza, RSV, or hMPV. Methods. Tis was a prospective global study in adults hospitalized with acute respiratory tract infection (40 centers, 12 coun- tries). Participants with infuenza, RSV, or hMPV were enrolled in a substudy and followed for up to 3 months postdischarge. Results. Overall, 366 infuenza, 238 RSV, and 100 hMPV-infected participants enrolled in the substudy. RSV participants were older and had greater frequency of risk factors and longer duration of symptoms before hospitalization than infuenza participants. Te RSV and hMPV groups received more bronchodilators, corticosteroids, and oxygen supplementation. No signifcant diferences in intensive care unit admissions or complications were observed. Readmission occurred in 20%–33% of patients within 3 months postdischarge, with the highest rates for RSV and hMPV. In-hospital death occurred in 2.5% of RSV, 1.6% of infuenza, and 2% of hMPV participants. In multivariate analyses, length of stay was independently associated with country, renal disease, and increased age; probability of receiving supplemental oxygen was associated with pathogen (hMPV > RSV > infuenza), abnormal chest x-ray, and increased age. Conclusions. Although infuenza is more frequent, the HARTI study demonstrates greater frequency of underlying risk factors and MRU for RSV and hMPV vs infuenza in hospitalized adults, indicating a need for efective interventions. Keywords. global prospective study; Infuenza; RSV; hMPV; medical resource utilization. Lower respiratory tract infections (LRTIs) are a leading cause of mortality and morbidity worldwide, resulting in almost 2.38 million deaths in 2016, making LRTI the sixth leading cause of mortality for all ages [1]. In a systematic analysis of the global burden of disease in adults in 2010, about 500   000 deaths annually were linked to influenza and 250 000 to res- piratory syncytial virus (RSV) infections [2]. In a prospective study among hospitalized adults aged ≥50 years, mortality was comparable between human metapneumovirus (hMPV) and RSV-infected patients [3]. Infuenza is a well-recognized respiratory pathogen, with annual epidemics afecting 5%–20% of the global unvaccinated population in all age groups, resulting in 3–5 million cases of severe illness and 250   000 to 500   000 deaths [2, 4, 5]. Te rates of serious infuenza illness and death are highest among persons aged <2 years or ≥65 years and those who are immunocompromised or have medical conditions such as asthma, chronic obstructive pulmonary disease (COPD), cardiovascular disease, or diabetes [6–9]. Tere is increasing yet incomplete evidence of the burden associated with RSV and hMPV infection in adults. A Downloaded from https://academic.oup.com/ofid/article/8/11/ofab491/6381446 by guest on 13 March 2023