To the Editor, The widespread clinical use of tamoxifen (TAM), a selective estrogen receptor (ER) modulator, warrants comprehensive real-world studies of its adverse events (AEs). Recently, there has been a demand for sex-based medicine. Ke et al.'s report helps healthcare providers recognize TAM-related AEs and understand sex differences and holds promise for potentially improving safety in clinical applications. 1 Ke et al. created subgroups of females and males from the FDA Adverse Event Reporting System, the US Individual Case Safety Reporting (ICSR) database, to investigate characteristic TAM-related AEs in each group.While we acknowledge the value of the study's findings, it is important to note some limitations in the statistical analysis method used, disproportionality analysis. Stratification, a common practice in epidemiology, is employed to mitigate bias due to confounding and is also beneficial in disproportionality analysis. [2][3][4] Therefore, the original paper's approach, in which the AE with the higher signal score in each group is considered to be the characteristic AE of that group, is correct. However, it must be recognized that when a signal is detected in both groups, this approach alone is insufficient to determine whether the signal is a characteristic AE of one of the groups.