br Patient specific factors such as age underlying disease

Patient-specific factors such as age, underlying disease, and surgical site have been identified as risk factors for intraoperative transfusion.4,5 In addition, intraoperative management of anticoagulation including antiplatelet therapy has been suggested to reduce intraoperative bleeding complications.4 However, few studies on the as-sociation of antithrombotics, relative to their duration of action, with intraoperative transfusion have been con-ducted. Therefore, we aimed to analyze the impact of antithrombotic therapy, according to drug HG-9-91-01 and duration of action, on intraoperative transfusion in oncology patients undergoing preoperative CGA.
2.1. Study population and data collection
This study is a retrospective analysis of prospectively collected data. We included patients aged 65 years or older who were scheduled for cancer surgery and who underwent comprehensive geriatric assessment (CGA) before surgery at the Geriatric Center of Seoul National University Bun-dang Hospital from January 2014 to June 2015.6 Patients with solid tumors who underwent all types of cancer sur-gery procedures were included, regardless of cancer stage. Patients who refused surgery or did not undergo cancer surgery were excluded.
Baseline characteristics of participants were collected from electronic medical records, including age, sex, body mass index (BMI), cancer type, and comorbidities. Serum
creatinine, lean body weight, sex, and age were used to estimate renal function with the CockcrofteGault equa-tion. Risk of delirium was measured using the Nursing Delirium Screening Scale with scores ranging from 0 to 5.7 All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional and/or national research committee (the Seoul National University Bundang Hospital Institu-tional Review Board, B-1811-507-102) and with the 1964 Helsinki declaration and its later amendments or compa-rable ethical standards. Informed consent was obtained
from all individual participants included in the study.
2.2. CGA of cognitive function and preoperative medication history
Preoperative CGA was performed using a tool established by a geriatrics team composed of geriatricians, nurse spe-cialists, dietitians, and pharmacists. The pharmacists were responsible for medication reviews. Cognitive function was evaluated using the Korean version of the Mini-Mental Sta-tus Examination (MMSE-KC) with scores ranging from 0 to 30 (dementia score < 17).8
The medication reviews were performed as follows: 1) Patients were instructed to bring records of their pre-scriptions or the actual medications to the CGA, and 2) pharmacists interviewed the patients and their caregivers to clarify all prescription and non-prescription medications. Information on medications only taken as needed (PRN) was also obtained. The total number of medications per pa-tient, preoperative discontinuation-requiring medications (PDRMs), and potentially inappropriate medications (PIMs) were analyzed.
PDRMs were defined as medications that should be dis-continued before surgery due to surgical risks; systole included antithrombotic agents, nonsteroidal anti-inflammatory drugs (NSAIDs), and streptokinase/strepto-dornase, which pose risks of postoperative hemorrhage; metformin, due to the risk of lactic acidosis; exogenous hormones, due to the risk of venous thromboembolism; and herbal medications, due to uncertainty about their actual contents.6 Antithrombotic medications were subclassified as short-acting and long-acting anticoagulants and short-acting and long-acting antiplatelet agents, according to their mechanism and duration of action.9e13 Peripheral vasodilators that have antiplatelet activity were also included in the bleeding risk category (Table 1).14e18