Objective  To investigate the mediating role of depression in sleep and preoperative frailtyin elderly patients with gastrointestinal cancer.

  Methods  A total of 219 elderly patients with gastrointestinal cancer were selected by convenience sampling method. The general information questionnaire, Pittsburgh Sleep Quality Index, Patient Health Questionnaire-9 and Tilburg Frailty Indicator were used to investigate the correlations between depression as well as sleep and preoperative frailty.

  Results  Sleep and depression had direct positive effects on preoperative frailty in elderly patients with gastrointestinal cancer (β=0.326, 0.179, t=3.905, 1.977, P < 0.05); depression partially mediated in sleep and preoperative frailty (β=0.179, VAF=47.97%, P=0.043).

  Conclusion  Depression and sleep are closely related to preoperative frailty, and the latter can directly affect preoperative frailty, or indirectly affect the occurrence of preoperative frailty through depression. Medical staff should pay attention to the evaluation and treatment of sleep quality and depression of elderly patients before operation. For patients with poor preoperative sleep quality and difficulty in improvement, we can alleviate the preoperative depression to reduce the incidence of preoperative frailty.