Objective To review the current application of sample size estimation in real-world studies (RWS), analyse parameter settings and commonly used methods, and provide methodological guidance for researchers conducting RWS. Methods First, ClinicalTrials.gov was searched to identify RWS with documented sample size calculations. Key information was extracted for descriptive analysis. Secondly, critical parameters and common estimation methods for RWS sample size calculations were systematically reviewed, and strategies were proposed for addressing common challenges. Finally, relevant international reporting standards were interpreted. Results The literature review included 44 clinical trials with a wide range of sample sizes (30 to 30 400 cases). While most studies detailed the sample size estimation process, the parameter settings were often incomplete and many failed to adequately consider the characteristics of real-world data. Therefore, we proposed key parameters for RWS sample size estimation, including effect size, significance level and statistical power. Researchers should also consider issues such as heterogeneity, confounding factors and data quality. This study clarified the essential elements of reporting sample size estimation. Conclusion Methodological guidance for real-world evidence sample size estimation is lacking. We advise researchers to standardise reporting procedures for sample size estimation in future studies and to set parameters reasonably based on research objectives, study design types and data characteristics. This will enhance the transparency and scientific rigour of real-world evidence.
ObjectiveTo evaluate the quality of randomized controlled trials (RCTs) of Chinese medicine (TCM) formulated granules published in core journals in China. MethodsComputerized searches were conducted in CNKI, VIP, WanFang Data and CBM databases. The publicly published RCTs of TCM formulated granules were collected, with sources from Peking University Core, CSSCI and EI. The following information was extracted: including title, the first author, the journals name, type of disease, year of publication, and source of drug. The included studies were evaluated using the CONSORT extension for CHM formulas (CONSORT-CHM formulas 2017), which included 25 items from title, abstract and keywords, introduction, research methods, steps, results, discussion, and other information. ResultsA total of 125 papers were included, which mainly included digestive system diseases (n=25), respiratory system diseases (n=17), and circulatory system diseases (n=17). The results showed that the overall reporting quality of RCTs of TCM formulated granules was poor. After the publication of the CONSORT-CHM formulas 2017, the reporting quality of RCTs of TCM formulated granules had no significant changes, while some items were still reported with poor quality. For example, 42.2% of RCTs did not adequately report how to generate allocation sequence, 93.3% of RCTs did not adequately report allocation concealment, and 62.2% of RCTs did not adequately report how to solve the missing data. ConclusionThe quality of RCTs reports on TCM formula granules published in Chinese journals still needs to be improved. It is recommended that researchers, journals and reviewers attach importance to the application of CONSORT-CHM formula throughout the whole process of paper writing. In the future, more scientific and detailed requirements should be put forward for trial design and reporting standards in line with the characteristics of clinical trials of TCM formula granules.