Abstract Background: This study examines the structural consistency of a recent South Korean observational cohort regarding post-COVID-19 vaccination oncological incidence.Objective: To compare the internal metrics of the study cohort with official South Korean national benchmark statistics. Methods: Comparison was conducted across three parameters: crude incidence rates, demographic distribution, and stratified incidence differences relative to 2022 cancer registry data. Results: Findings show a -26.0% discrepancy in total incidence, a -32.5% difference in elderly population representation, and a -45.1% lower incidence in the unvaccinated control group compared to national data. Conclusion: In light of the evidence, a selection bias emerges which, according to epidemiological standards, could suggest that the observed associations are spurious. Further investigation using non-aggregated data is necessary for a definitive assessment of the results' generalizability.
Marco Roccetti (Fri,) studied this question.