Association of pre-operative medication use with post-surgery mortality and morbidity in oncology patients receiving comprehensive geriatric assessment

Background: Comprehensive geriatric assessment (CGA) has become a predictor for elderly cancer patients in post-surgical complications, including post-discharge institutionalization and mortality. Aims: To determine whether pre-operative medication use is associated with post-operative morbidity and mortality in oncology patients receiving CGA. Methods: Patients aged 65 years or older who were scheduled for cancer surgery and presented for CGA were included in the present study. Baseline characteristics of patients were collected from electrical medical records, and pre-operative medication review was performed. The primary outcome was death within 30 days after surgery and post-discharge institutionalization. Results: A total of 475 cancer patients were included. Among them, three patients died within 30 days after surgery and 14 patients were discharged to another institution. All patients who died within 30 days after surgery had polypharmacy with marginal significance (P = 0.087). Multivariate analysis models were constructed using significant factors for post-surgery institutionalization from univariate analysis: Model I (polypharmacy and transfusion), Model II (polypharmacy and infection), and Model III (polypharmacy, transfusion, and infection). Infection was the most significant factor. Its adjusted odds ratio was as large as 11.1 and attributable risk was almost 91%. In pre-surgery medication use, only polypharmacy showed significant association with post-discharge institutionalization. Attributable risk of polypharmacy was around 75%. Conclusions: It is possible that pre-operative medication use has impact on death and post-discharge institutionalization in geriatric oncology patients, further highlighting the importance of medication optimization for elderly patients with cancer surgery.