Perioperative Risk Models

Over the past 80 years, various risk models have been published attempting to aid clinical decision-making in the perioperative period. The primary goal of such models is to objectively classify risks numerically or into categories that can be readily understood by clinicians and patients. Some models have been extrapolated from nonsurgical patient populations, whereas others have been derived and validated solely in surgical cohorts. The scope of perioperative medicine is broad, and a discussion of risks surrounding the surgical period can vary from general statements noting whether patients are acceptable candidates, to detailed problem-specific discussions. We present here an outline of key preoperative models developed over time. These models relay general risk assessments as well as problem- and specialty-specific assessments.