The practice-makes-perfect hypothesis in the context of other production concepts in health care.

Many studies have found a significant relationship between the volume of specific diagnoses and procedures and patient outcomes. Often, these studies have cited the "practice-makes-perfect" hypothesis as a potential explanation. However, the expression "practice-makes-perfect" hypothesis is inappropriate in most circumstances. This article suggests using the expression "routine" hypothesis instead. In addition, this article compares the routine hypothesis with other familiar concepts from industrial production, which also aim at explaining the relationship between factor input and output in health care: economies of scale, economies of scope, the learning curve, and the focused factory. To point out subtle differences among the concepts, this article suggests a taxonomy organized by type of output and outcome. This taxonomy may help ensure the appropriate use of terminology when applying these concepts.