Can readmission rates be used as an outcome indicator?

There has been interest in the use of readmission rates as an outcome indicator in hospitals since at least 1965, when in their pioneering study Acheson and Barr suggested that the readmission rate might serve "as an index of the quality of medical care."' This idea has lately regained ground,2 and readmission rates have been described as "one of the few potential measures available from routine statistics for assessing outcome."3 This paper attempts to clarify how far readmission rates can be useful as an indicator of outcome.