The protocol was approved by the Swedish ethical review board (2021-02634, amendment 2021-04572, approval date 25 May 2021 and 22 September 2021) and the Swedish medical products agency (5.1-2020-36673, approval date 06 July 2021). The trial was registered on ClinicalTrial.gov (NCT04842448), 13 April 2021, and on EudraCT (2021-000764-30), 21 May 2021, before the start of the trial.
Patient representatives from the post-COVID association in Sweden (Svenska Covidföreningen) were involved and approved the trial design.
The protocol includes a detailed description and rationale for the primary and main secondary endpoints, including patient reported outcomes (PRO) in line with Standard Protocol Items: Recommendations for Interventional Trials (SPIRIT) SPIRIT-PRO Extension guidelines.21 The full protocol is published and available with open access.22
The trial was conducted in accordance with The Declara- tion of Helsinki, ICH-GCP, local and national regulations and is reported according to Consolidated Standards of Reporting Trials (CONSORT) Harms 2022 guidelines.23
The trial was monitored by an independent monitoring organisation, Karolinska Trial Alliance (KTA), before, during and after the trial according to the monitoring plan.
An independent data safety monitoring board (DSMB) reviewed the data three times during the trial. A charter delineating their operating guidelines and stop- ping rules for terminating individual subjects, a portion or all the trial prematurely, was drawn up and agreed on before the trial started. The DSMB is composed of three experts in their respective disciplines of medicine, clin- ical trial methodology and conduct. The members of the DSMB, meeting plan and responsibilities are specified in the original protocol (p6 and 44).