Diagnosis-related groups and severity. ICD-9-CM, the real problem.
D000043:Abstracting and Indexing; D003365:Costs and Cost Analysis; D003953:Diagnosis-Related Groups; D004194:Disease / Q000145:classification*; D006801:Humans; D007350:Insurance, Hospitalization / Q000191:economics; D007391:International Cooperation; D006278:Medicare / Q000191:economics; D012051:Reimbursement Mechanisms; D014481:United States