2026-04-17T08:05:29Zhttps://recercat.cat/oai/request

oai:recercat.cat:2117/4465062026-02-09T08:03:55Zcom_2072_1033col_2072_452950

urn:hdl:2117/446506 Identifying clinically useful COVID-19 population and emergency department phenotypes across the pre-Omicron and Omicron periods Rodriguez-Idiazabal, Lander Fernández Martínez, Daniel Quintana López, José María García Asensio, Julia Legarreta Olabarrieta, María José Barrio Beraza, Irantzu Àrees temàtiques de la UPC::Economia i organització d'empreses::Aspectes socials COVID-19 Phenotype Cluster analysis Preventive medicine Public Health Background Rapidly phenotyping patients can enhance healthcare management during new pandemic outbreaks. This can be accomplished through data-driven unsupervised methods that do not require clinical outcomes to be available. This study aimed to identify and compare phenotypes of COVID-19 patients and the subset of those patients who visited emergency departments using clustering techniques based on a limited set of easily accessible variables across different stages of the pandemic. Methods We conducted a population-based retrospective study that included all reported adult COVID-19 patients in the Basque Country from March 1, 2020, to January 9, 2022. Phenotypes were identified separately for the pre-Omicron and Omicron periods in an unsupervised manner using clustering techniques based on easily obtainable clinical and sociodemographic variables. The clinical characteristics of the phenotypes were compared, and subsequently their association with the clinical outcomes was assessed. Results Four phenotypes were identified in both the general population and the emergency department sub-group in the pre-Omicron period, whereas three phenotypes were extracted in Omicron. Within each scenario, these phenotypes varied significantly in age and comorbidity rates, leading to varying associations with COVID-19 outcomes. Despite their similarities, the emergency department phenotypes consistently experienced worse outcomes than their general population counterparts. Moreover, the population and emergency department phenotypes identified during the Omicron period resembled those from the pre-Omicron stage, suggesting stable phenotypic structures throughout the pandemic. Conclusions This study highlights the potential of phenotype identification based on a few accessible variables for a meaningful segregation of patients. This approach could be extended to future pandemics as a preventive public health strategy, especially considering the growing likelihood of facing new ones. This work was supported in part by grants from the Departamento de Educación, Política Lingüística y Cultura del Gobierno Vasco [IT1456-22]; the health outcomes group from Galdakao- Barrualde Health Organization; the Kronikgune Institute for Health Service Research; Instituto de Salud Carlos III (ISCIII) through the project "RD16/0001/0001" (Red de Investigación en Servicios de Salud en Enfermedades Crónicas) and the project “RD21CIII/0003/0017” (Red de Investigación en Cronicidad, Atención Primaria y Prevención y Promoción de la Salud); BIOSTATNET "RED2022-134202-T" (BIOSTATNETX: Avanzando en la Investigación de Excelencia en Bioestadística a Nivel Nacional e Internacional) and co-funded by the European Union, and the Basque Government through BMTF ‘‘Mathematical Modeling Applied to Health’’ Project. The work of LR was financially supported by the Ministry of Science and Innovation through BCAM Severo Ochoa accreditation [CEX2021-001142-S]. The work of IB was financially supported in part by grants from the Ministry of Science and Innovation through BCAM Severo Ochoa accreditation [CEX2021-001142-S/MICIN/AEI/https://doi.org/10.13039/501100011033] and also by the Basque Government through the BERC 2022–2025 program. DF is a Serra-Húnter Fellow, a member of the Centro de Investigación Biomédica en Red de Salud Mental (CIBERSAM), and his work has been supported by MICIU/AEI/https://doi.org/10.13039/501100011033 (Spain) and by FEDER (EU)[PID2023-148033OB-C21], and by grant 2021 SGR 01421 (GRBIO) administrated by the Department de Recerca i Universitats de la Generalitat de Catalunya (Spain). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. Peer Reviewed Postprint (published version) 2025-08-04 Article https://archpublichealth.biomedcentral.com/articles/10.1186/s13690-025-01681-6 http://creativecommons.org/licenses/by-nc-nd/4.0/ Open Access Attribution-NonCommercial-NoDerivatives 4.0 International Springer