Learning, forgetting and technology substitution in the treatment of coronary artery disease

Statistics from the World Health Organization list Coronary Artery Disease (CAD) as the number two cause of death among 15--59 year olds and number one cause of death among those 60 and over worldwide. Given the number of lives impacted by CAD, the amount of research centered on treating, preventing and measuring the impacts of this disease is not surprising. This dissertation furthers this research by addressing two issues related to economics of the intervention of CAD; the impact of the human capital depreciation of cardiac surgeons on the health outcomes of their patients, and the substitutability of a new and innovative surgical intervention technique for an established and relatively effective technique.;Essay one addresses the depreciation of surgeons' human capital by investigating whether the level of surgeon volume in the most recent quarter lead to more of a reduction in patient mortality than that of the previous quarter. This helps to address whether a surgeons more recent experience has a larger impact on their human capital than earlier experience. Essay two addresses the impact of the temporal distance between each surgery a surgeon performs on patient mortality. Taken together the findings of these two essays suggest that the human capital of surgeons does depreciate, and it does so over a relatively short period of time, which has implications for efficiency in the intervention of CAD.;The third essay addresses the substitutability of percutaneous transluminal coronary angioplasty (PTCA) for coronary artery bypass graft surgery (CABG) across the population of Pennsylvania from 1994--2004. This study builds on previous work (Cutler and Huckman, 2003) and suggests that PTCA is a substitute for CABG in the marginal population (measured by severity) and that the introduction of a follow on technology, the coronary stent, may have been a driver of much of the diffusion of the use of PTCA as an alternative to CABG.