Rate of Testing in US Ambulatory Preoperative Visits Compared With General Medical Examinations, 1997-2010
The vertical line at year 2002 indicates the cutoff for the comparison of change in testing rates for preoperative visits to general medical examinations. Data points represent combined data for 2-year increments (eg, 1997-1998, 1999-2000), but cardiac stress testing rates were averaged for 3-year instead of 2-year intervals (except in 1997-1998) to improve statistical reliability. ECG indicates eletrocardiography.