Preoperative ANemiA among the elderly undergoing major abdominal surgery (PANAMA) study: Protocol for a single-center observational cohort study of preoperative anemia management and the impact on healthcare outcomes

INTRODUCTION: Preoperative anemia and old age are independent risk factors for perioperative morbidity and mortality. However, despite the high prevalence of anemia in elderly surgical patients, there is limited understanding of the impact of anemia on postoperative complications and postdischarge quality of life in the elderly. This study aims to investigate how anemia impacts elderly patients undergoing major abdominal surgery in terms of perioperative morbidity, mortality and quality of life for 6 months postoperatively. METHODS AND ANALYSIS: We will conduct a prospective observational study over 12 months of 382 consecutive patients above 65 years old, who are undergoing elective major abdominal surgery in Singapore General Hospital (SGH), a tertiary public hospital. Baseline clinical assessment including full blood count and iron studies will be done within 1 month before surgery. Our primary outcome is presence of morbidity at fifth postoperative day (POD) as defined by the postoperative morbidity survey (POMS). Secondary outcomes will include 30-day trend of POMS complications, morbidity defined by Clavien Dindo Classification system (CDC) and Comprehensive Complication Index (CCI), 6-month mortality, blood transfusion requirements, days alive out of hospital (DaOH), length of index hospital stay, 6-month readmission rates and Health Related Quality of Life (HRQoL). HRQoL will be assessed using EuroQol five-dimensional instrument (EQ-5D) scores at preoperative consult and at 1, 3, and 6 months. ETHICS AND DISSEMINATION: The SingHealth Centralised Institutional Review Board (CIRB Ref: 2017/2640) approved this study and consent will be obtained from all participants. This study is funded by the National Medical Research Council, Singapore (HNIG16Dec003) and the findings will be published in peer-reviewed journals and presented at academic conferences. Deidentified data will be made available from Dryad Repository upon publication of the results.