@inbook{10.7249/mr1500cms.12, ISBN = {9780833031488}, URL = {http://www.jstor.org/stable/10.7249/mr1500cms.12}, abstract = {In this section, we discuss adding comorbidities and complications to the classification system. We began with a variety of hypotheses about which conditions affect cost, each suggested by a clinician. We tested each hypothesis to determine whether the nominated conditions were in fact associated with increased cost after controlling for FRG. These tests resulted in a list of conditions that are correlated with higher costs and that our clinical consultants believe actually cause an increase in costs. Finally, we evaluated alternative models for accounting for the cost of comorbidities. Some codes that were found to affect cost were eliminated from}, bookauthor = {Grace M. Carter and Melinda Beeuwkes Buntin and Orla Hayden and Jennifer Kawata and Susan M. Paddock and Daniel A. Relles and Gregory K. Ridgeway and Mark E. Totten and Barbara O. Wynn}, booktitle = {Analyses for the Initial Implementation of the Inpatient Rehabilitation Facility Prospective Payment System}, pages = {99--154}, publisher = {RAND Corporation}, title = {COMORBIDITIES}, year = {2002} }