Attachments
Abstract
Background: A proportion of those infected with SARS-CoV-2 experience long-term symptoms. Definitions of this emerging condition vary, leading to complexities in advancing research and clinical policy development. Over the course of the pandemic, various terminology including long COVID, long-haul COVID or the WHO-recommended post COVID-19 condition have been proposed. Still, a globally standardized clinical case definition of this condition remains lacking.
Aim: We aimed to determine the most important domains and variables for inclusion into a globally relevant and standardized clinical case definition for post COVID-19 condition.
Methods: We conducted a two-round Delphi exercise, followed by a mixed, iterative consensus process. Five groups of stakeholders were engaged: patients, patient-researchers, external experts, WHO staff and others. Participants were chosen for balanced representation across age, gender, specialty, area of expertise and geography. Pre-defined statistical thresholds for consensus and disagreement were established.
Results: There were 265 participants in Round 1, with 241 complete responses and 24 incomplete responses. In Round 2 there were 195 participants, with 178 complete responses and 17 incomplete responses. From an initial list of 14 domains identified, 11 were selected in Round 1, and one was added in Round 2 for a final total of 12. Each domain consisted of multiple questions and a total of 45 items were asked in the survey. A clinical case definition was developed with those domains that reached the pre-defined thresholds and further expanded with values that reached borderline significance. Wording was trimmed in an iterative process with patients and patient-researchers.
Conclusion: Through a large global consensus process, a working clinical case definition of post COVID-19 condition, including 12 domains, is now available for use in all settings. This definition may change as new evidence emerges and our understanding of the consequences of COVID-19 continues to evolve.