More than 24 million hospital stays (63% of all stays) in 2011 involved some type of procedure. Some of these procedures (such as a chest X-ray or skin biopsy) occurred outside of the operating room (OR). Others were major OR procedures (such as hip replacement or heart valve repair). Hospital stays that involve OR procedures are more costly, on average, than stays that do not involve OR procedures.

Over time, some OR procedures have become more prevalent, while others have decreased in frequency. For instance, prior research has found that the volume of coronary artery bypass graft (CABG) decreased by 70 percent from 1997 to 2007, while the volume of percutaneous transluminal coronary angioplasty (PTCA) increased by 20 percent during this same time period. Such trends may reflect changing standards in surgical care, the introduction of new surgical techniques, a shift in procedure setting from inpatient to outpatient, or an aging population, among other reasons.

This Statistical Brief presents data from the Healthcare Cost and Utilization Project (HCUP) on trends in OR procedures from 2001 through 2011. For this Statistical Brief, OR procedures are defined using the HCUP procedure classes tool. In this tool, OR procedures are identified based on diagnosis-related groups (DRGs) that use physician panels to determine whether the procedure would be performed in a hospital OR in most hospitals. The findings in this Statistical Brief represent an update of 2007 statistics reported by Elixhauser and Andrews. We present the 2001 and 2011 volume of OR procedures by major clinical body system. For selected high-volume procedures, we provide the trends and identify differences over the 11-year period examined. All differences between estimates noted in the text are significantly different at the .001 level or better.