Substitutability of a process innovation in medical diagnosis: some empirical results

The health sectors in many countries have been increasing in relative size, and medical innovations have been identified by some as a factor contributing to the rise in health expenditures. This paper begins by reviewing the various approaches that economists have employed to determine the connection, if any, between rising health expenditures and new medical technologies. It is then argued that another way to approach the issue is to determine if innovations have substituted for previously existing technologies. Thus this method cannot be applied to product innovations: it is restricted to process innovations. This procedure is applied to the innovation of fibre optic colonoscopy, a procedure for diagnosing diseases/conditions in the lower gastrointestinal tract. The data relate to private medical practice in Australia which operates on a fee-for-service basis. The empirical results indicate no evidence of substitution of the 'new' for the 'old' technology. Thus, there is some reason to believe that this innovation will have contributed to rising health expenditures for diagnosis of the lower gastrointestinal tract. The paper concludes by considering policy options that could address the issue.