This letter responds to comments by Zhu et al. regarding the study on the impact of time-to-surgery on survival and quality of life in oral cancer. The authors clarify that the analyses reported were univariate Cox regressions, for which the commonly cited rule of ten events per variable does not apply, as it pertains mainly to multivariable models. They also reiterate that a multivariate analysis was intentionally not performed due to the limited number of disease-free survival events, to avoid model overfitting. Furthermore, they clarify that the COVID-19 pandemic could not have influenced the study results, since the patient cohort was treated between 2008 and 2015. Finally, the authors acknowledge the need for larger prospective studies to better define the relationship between surgical delay, survival, and quality of life in oral cancer.
