Changing patterns of surgical care in the United States, 1980-1995.

National inpatient and ambulatory surgery data were combined to examine changes over time in the location and amount of surgical care. The main pattern was a decline in the rate of inpatient operations that was outweighed by growth in ambulatory operations. However, the rate of inpatient operations did not decrease for patients age 65 years or over, despite the growth in ambulatory surgery. Other patterns seen for specific types of operations were the substitution of ambulatory for inpatient operations, increases primarily in the rate of inpatient operations, and decreases in total operations. These patterns have implications for control of health care costs.