Accuracy of Diagnostic Coding for Medicare Patients under the Prospective-Payment System

Abstract

Reimbursement of hospitals by Medicare under the prospective-payment system is based on patients' diagnoses as coded at discharge. During the period October 1984 through March 1985, we studied the accuracy of the coding for diagnosis-related groups (DRGs) in hospitals receiving Medicare reimbursement. We used a two-stage cluster method to sample 7050 medical records from 239 hospitals that were stratified according to size. Using blinded techniques with reliability checks, medical-record specialists reabstracted the International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) codes to assign correct DRGs to discharged patients. The correct DRGs were then compared with those originally assigned by the physician and the hospital administration.