Statistical analysis plan for the INHALEd nebulised unfractionated HEParin for the treatment of hospitalised patients with COVID-19 (INHALE-HEP) meta-trial

The INHALE-HEP meta-trial is a prospective collaborative individual participant data meta-analysis of randomised controlled trials and early phase studies, to evaluate whether inhaled nebulised UFH in hospitalised patients with COVID-19 who do not require immediate invasive mechanical ventilation, significantly reduces intubation (or death, for patients who died before intubation) at day 28 compared to standard care alone. Objective: In keeping with best practice and with the published protocol, a pre-specified statistical analysis plan has been described and made public before completion of patient recruitment and data collection into the INHALE-HEP meta-trial. Methods: Our statistical analysis plan was designed by the INHALE-HEP executive committee and statisticians and approved by the INHALE-HEP steering committee. We reviewed the data collected as specified in the meta-trial protocol and collected in individual contributing studies. We present information pertaining to data collection, pre-specified subgroups, and study outcomes. Primary and secondary outcomes are defined, and additional subgroup analyses of pre-defined variables are described. Results: We have described our methods for presenting the trial profile and baseline characteristics, as well as our Bayesian approach to monitoring and meta-analysing individual patient data, outcomes and adverse events. All analyses will follow the intention-to-treat principle, considering all participants in the treatment group to which they were assigned, except for cases lost to follow-up or withdrawn. Conclusion: To minimise analytical bias, we have developed a statistical analysis plan and made this available to the public domain before completion of patient recruitment and data collection into the INHALE-HEP meta-trial.