“…Participating hospitals are both community-based and academic with 1000 to 10,000 general and vascular surgery cases per year. 15 the mSqC database has been created and maintained on the principles and procedures of the American College of Surgeons' national Surgical quality improvement Program (ACS nSqiP), a national effort to assess the outcomes of operative interventions and improve the quality and safety of surgery. 16,17 Following ACS nSqiP methodology, the mSqC database records a "systematic sample," consisting of 40 consecutive cases in an 8-day cycle, with each cycle beginning on a different day of the week.…”