DRG migration: A novel measure of inefficient surgical care in a value-based world

Abstract Background Diagnosis-Related Group (DRG) migration, DRG 331 to 330, is defined by the assignment to a higher cost DRG due only to post admission comorbidity or complications (CC). Methods We assessed the 5% national Medicare data set (2011–2014) for colectomy (DRG's 331/330), excluding present on admission CC's and selecting patients with one or more CC's post-admission to define the impact on payments, cost, and length of stay (LOS). Results The incidence of DRG migration was 14.2%. This was associated with statistically significant increases in payments, hospital cost, and LOS compared to DRG 331 patients. Conclusions When DRG migration rate was extrapolated to the entire at risk population, the results were an increase of Centers for Medicare and Medicaid Services (CMS) cost by $98 million, hospital cost by $418 million, and excess hospital days equaling 68,669 days. These negative outcomes represent potentially unnecessary variations in the processes of care, and therefore a unique economic concept defining inefficient surgical care.