Dataset for article: Changes in evidence for studies assessing interventions for COVID-19 reported in preprints: meta-research study. BMC Med 18, 402 (2020).

This dataset was used in the analyses reported in Oikonomidi, T., Boutron, I., Pierre, O. et al. Changes in evidence for studies assessing interventions for COVID-19 reported in preprints: meta-research study. BMC Med 18, 402 (2020). https://doi.org/10.1186/s12916-020-01880-8. This project is ancillary to the COVID-NMA Living systematic review and network meta-analysis of Covid-19 trials: https://covid-nma.com/ The first spreadsheet entitled "key" includes the full description of the dataset.本数据集被应用于Oikonomidi T、Boutron I、Pierre O等学者发表的分析研究中，该研究题为《预印本报道的COVID-19干预措施评估研究的证据变化：元研究》，发表于《BMC医学》（BMC Med）2020年，第18卷，第402页，DOI标识：https://doi.org/10.1186/s12916-020-01880-8。本项目为COVID-NMA新冠临床试验活系统综述与网络元分析的附属研究，相关平台链接：https://covid-nma.com/。首个名为"key"的电子表格包含本数据集的完整说明。