The Clinical Frailty Scale is the Significant Predictor for in-Hospital Mortality of Older Patients in the Emergency Department [Response to Letter]

Dear editor

We are greatly honored to receive comments from Shen et al and respond as provided by the Editor-in-Chief. Our study entitled, “The Association Between Frailty Evaluated by the Clinical Frailty Scale and Mortality of Older Patients in the Emergency Department: A Prospective Cohort Study”, found that individuals with higher clinical frailty scale scores had the worse clinical outcomes.¹

First, the key characteristic of competing risks is the loss of a direct one-to-one relationship between cause-specific hazards and cumulative incidence and differing relationships between covariates and these two measures.² Our study defined primary outcome as all-cause 90-day mortality, in which the one-to-one relationship was preserved; thus, there were no competing risks.

Second, our study adjusted for age, sex, and triage acuity in the regression analysis. Additional factors suggested by Shen et al, such as the Charlson comorbidity index, organ failure assessment, physical activity, and disease complications, should be further explored in future research.

Finally, this study was conducted in an emergency department (ED) observation room to evaluate the impact of frailty on clinical outcomes in older adults. Only 63.6% of the participants were admitted. The relationship between delays in ED admission and mortality could be important; however, it could not be determined in this study.

We thank Shen et al for their valuable feedback on the study. We appreciate the insightful comments, which have provided valuable guidance for future research.