The National Survey of Ambulatory Surgery (NSAS) is the only national study of ambulatory surgical care in hospital-based and freestanding ambulatory surgery centers (ASCs). The NSAS was first conducted from 1994 to 1996, but it was discontinued due to lack of resources. The NSAS was conducted again in 2006. Efforts are now underway to include ambulatory surgery centers in the National Hospital Ambulatory Medical Care Survey (NHAMCS). The NHAMCS website provides more information on the efforts.
A separate web page has been created for the National Hospital Discharge Survey (NHDS). The new web address for NHDS is /nchs/nhds.htm