Psoas muscle mass index as a predictor of long-term mortality and severity of complications after major intra-abdominal colorectal surgery – A retrospective analysis

•Identifying patients at risk of adverse postoperative outcomes can enable clinicians to optimise care.•Most patients undergoing major elective abdominal surgery have preoperative imaging.•Psoas muscle area can be measured in computed tomography scans and normalized to height - psoas muscle index(PMI).•PMI is an independent predictor of mortality and severity of complications after major abdominal surgery.•PMI is a quick, practical and feasible measuring method that can easily be implemented in clinical practice.