Assessing change in patient-reported quality of life after elective surgery: protocol for an observational comparison study.

Despite their widespread use, the two main methods of assessing quality of life after surgery have never been directly compared. To support patient decision-making and study design, we aim to compare these two methods. The first of these methods is to assess quality of life before surgery and again after surgery using the same validated scale. The second is simply to ask patients whether or not they think their post-operative quality of life is better, worse, or the same. Our primary objective is to assess agreement between the two measures. Secondary objectives are to calculate the minimum clinically important difference (MCID) and to describe the variation across surgical specialties. To accomplish these aims, we will administer surveys to patients undergoing elective surgery, both before surgery and again 30 days after surgery. This protocol follows detailed guidelines for observational study protocols.