Assessing the effectiveness of postacute care rehabilitation.

This commentary reviews a number of issues related to determining the effectiveness of postacute care including what it is (in terms of type and site of care), how to tease out the critical elements (what components of this multifaceted process are essential), the role of research designs (given the logistic difficulties of doing randomized trials, how can nonexperimental designs be used to the greatest advantage), how to assess the relation between treatment and outcomes, measurement issues (what, when, how), correcting for case mix, and potential payment schemes.