Monitoring excess unplanned return to theatre following colorectal cancer surgery

BackgroundTo develop a risk‐adjustment model for unplanned return to theatre (URTT) outcomes following colorectal surgeries in Australia and New Zealand hospitals and apply top‐down and bottom‐up statistical process control methods for fair comparison of hospitals and surgeons’ URTT rates.MethodsWe analysed URTT outcomes from hospitals contributing data to the Bi‐National Colorectal Cancer Audit clinical registry between 2007 and 2016. Preoperative and intraoperative covariates were considered for risk adjustment. A risk‐adjusted rate funnel plot was prepared for between‐hospital comparisons and identification of outlying hospitals with unusually high rates of URTT. Cumulative observed‐minus‐expected charts with cumulative sum signals were then presented for surgeons within an outlying hospital.ResultsThe study included 15 134 patients and 166 surgeons across 70 hospitals. The weighted average URTT rate was 5.2%. The risk‐adjustment model identified 12 preoperative and intraoperative variables that significantly raise the risk of URTT: male sex, American Society of Anesthesiologists score, emergency admissions, conversion entry, left hemicolectomy, total colectomy, proctocolectomy,