Characterising Long Covid: a living systematic review update with controlled studies

The authors have withdrawn their manuscript owing to a reporting error that we have identified in the conduct of this updated systematic review. On 7th March 2022 we made changes to the original protocol published in F1000, to highlight the need to keep up with the evolving landscape of Covid-19 and Covid-19 research and focus on comparative, controlled studies. The revisions included also changes in data extraction and analysis that would be needed to do so. These changes were done in consultation with members of the Long COVID Support Group. However, we omitted to publicize these changes in an accessible, modified version of our protocol, and/or by updating our preregistered PROSPERO record (CRD42020211131) and F1000 publication, prior to commencing and completing these stages of the process. In this manuscript, which reports the revised analyses, we have consequently also omitted to explicitly describe these changes as important deviations from the published protocol. Additionally, following rapid, sustained, and continuous growth in the conduct and reporting of eligible primary studies, it has become clear that, with or without the changes described above, we do not have sufficient capacity or resources to transition our baseline systematic review to being regularly updated using a living systematic review approach. Therefore, the authors do not wish this work to be cited as reference for the project. If you have any questions, please contact the corresponding author. ### Competing Interest Statement All authors have completed the ICMJE uniform disclosure form and declare: no support from any organisation for the submitted work; no financial relationships with any organisations that might have an interest in the submitted work in the previous three years. JCS declares he is an individual living with long-term symptoms of probable Covid-19. All other authors declare no other relationships or activities that could appear to have influenced the submitted work. ### Funding Statement This work was supported by the UK Foreign, Commonwealth and Development Office and Wellcome [215091/Z/18/Z] and the Bill & Melinda Gates Foundation [OPP1209135] and the EU FP7 project PREPARE (602525). ### Author Declarations I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained. Yes I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals. Yes I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance). Yes I have followed all appropriate research reporting guidelines and uploaded the relevant EQUATOR Network research reporting checklist(s) and other pertinent material as supplementary files, if applicable. Yes