TY - JOUR PB - BMC A1 - Munblit, Daniel A1 - Nicholson, Timothy R A1 - Needham, Dale M A1 - Seylanova, Nina A1 - Parr, Callum A1 - Chen, Jessica A1 - Kokorina, Alisa A1 - Sigfrid, Louise A1 - Buonsenso, Danilo A1 - Bhatnagar, Shinjini A1 - Thiruvengadam, Ramachandran A1 - Parker, Ann M A1 - Preller, Jacobus A1 - Avdeev, Sergey A1 - Klok, Frederikus A A1 - Tong, Allison A1 - Diaz, Janet V A1 - De Groote, Wouter A1 - Schiess, Nicoline A1 - Akrami, Athena A1 - Simpson, Frances A1 - Olliaro, Piero A1 - Apfelbacher, Christian A1 - Rosa, Regis Goulart A1 - Chevinsky, Jennifer R A1 - Saydah, Sharon A1 - Schmitt, Jochen A1 - Guekht, Alla A1 - Gorst, Sarah L A1 - Genuneit, Jon A1 - Reyes, Luis Felipe A1 - Asmanov, Alan A1 - O'Hara, Margaret E A1 - Scott, Janet T A1 - Michelen, Melina A1 - Stavropoulou, Charitini A1 - Warner, John O A1 - Herridge, Margaret A1 - Williamson, Paula R JF - BMC Medicine KW - Science & Technology KW - Life Sciences & Biomedicine KW - Medicine KW - General & Internal KW - General & Internal Medicine KW - COVID-19 KW - COVID-19 sequalae KW - Long COVID KW - Post-acute sequelae of SARS-CoV-2 infection KW - PASC KW - Post-COVID-19 condition KW - Outcomes KW - Core Outcome Set KW - RESPIRATORY-FAILURE KW - SURVIVORS VL - 20 N1 - This work is licensed under a Creative Commons Attribution 4.0 International License. The images or other third-party material in this article are included in the Creative Commons license, unless indicated otherwise in the credit line; if the material is not included under the Creative Commons license, users will need to obtain permission from the license holder to reproduce the material. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/ IS - 1 N2 - BACKGROUND: A substantial portion of people with COVID-19 subsequently experience lasting symptoms including fatigue, shortness of breath, and neurological complaints such as cognitive dysfunction many months after acute infection. Emerging evidence suggests that this condition, commonly referred to as long COVID but also known as post-acute sequelae of SARS-CoV-2 infection (PASC) or post-COVID-19 condition, could become a significant global health burden. MAIN TEXT: While the number of studies investigating the post-COVID-19 condition is increasing, there is no agreement on how this new disease should be defined and diagnosed in clinical practice and what relevant outcomes to measure. There is an urgent need to optimise and standardise outcome measures for this important patient group both for clinical services and for research and to allow comparing and pooling of data. CONCLUSIONS: A Core Outcome Set for post-COVID-19 condition should be developed in the shortest time frame possible, for improvement in data quality, harmonisation, and comparability between different geographical locations. We call for a global initiative, involving all relevant partners, including, but not limited to, healthcare professionals, researchers, methodologists, patients, and caregivers. We urge coordinated actions aiming to develop a Core Outcome Set (COS) for post-COVID-19 condition in both the adult and paediatric populations. EP - 13 UR - https://doi.org/10.1186/s12916-021-02222-y ID - discovery10144042 Y1 - 2022/02/04/ TI - Studying the post-COVID-19 condition: research challenges, strategies, and importance of Core Outcome Set development AV - public ER -