Changes in the use of diagnostic technologies among Medicare patients, 1985 and 1990

This paper examines changes in the use of selected diagnostic technologies for Medicare patients in 1985 and 1990. The analysis compares patients across five common, medical tracer conditions: acute myocardial infarction (AMI), congestive heart failure (CHF), stroke, pneumonia, and gastrointestinal (GI) hemorrhage. The relationship of hospital characteristics to patterns of technology use was assessed by grouping hospitals by a composite measure of "costliness." The overall use of 21 diagnostic tests rose by 27% over the 5-year period. Increases were most marked among the three cardiovascular tracers and for related technologies, such as cardiac angiography and cardiac ultrasound. There was evidence that newer technologies partially replaced older diagnostic tests that were used for similar indications: rates of noninvasive cerebrovascular imaging rose while rates of cerebral angiography declined. However, for several common, long-established tests, such as electrocardiogram and chest radiograph, there were consistent increases that are unexplained. High-cost hospitals performed diagnostic tests at much higher rates than lower-cost hospitals in both 1985 and 1990, but the rate of increase in test use across the two study years was generally greater for the lower-cost hospitals.