Physiologic assessment of surgical diagnosis-related groups

Although (diagnostic related groups) DRGs were originally devised as a research instrument for the evaluation of medical resource allocation, no studies have been reported that compare the actual physiologic status of patients with DRG classification. At the Westchester Medical Center, a University tertiary referral center, 100 consecutive high-risk elective surgical patients entered a preoperative intensive care unit for a prospective analysis of physiologic assessment, resource utilization, DRG classification, and outcome. Swan-Ganz catheters inserted 1 or 2 days before surgery were used to compute physiologic profiles and stage according to previously published criteria. Risk was determined by age, associated conditions, and magnitude of the proposed operation. There were no patients in stage 1; 55% in stage 2; 41% in stage 3; and 4% in stage 4, which accounted for three of the four total deaths. The 41% of patients over age 70 all had DRG comorbidity factors, but none died. All in stages 3 and 4 had comorbidity factors, as did 87% in stage 2. In 53% of the patients, the physiologic profile provided data necessary for preoperative "fine tuning"; in 37%, for volume expansion; in 23%, for inotropic therapy; and in 17%, for pulmonary therapy. Reoperation was required in 17% and contributed to the long average length of stay (LOS) of 24.5 days. In spite of case severity and comorbidity factors, LOS in the postoperative ICU was only 3 days. There were no significant differences in patients with cancer DRGs. Significant differences between stages 2 and 3 were found for pulmonary wedge pressure, right ventricular stroke work, pulmonary vascular resistance, and pulmonary shunt fraction. The 4% who died all had advanced liver disease. Although the DRG system as set up by the Health Care Financing Administration (HCFA) correctly predicts that age and comorbidity factors lead to increased utilization of resources, the extent to which they underestimate the increased needs of these patients will lead to financial disaster. Compensation for comorbidity factors and advanced age are not cumulative, but patients over 70 had an average of 2.5 comorbidity factors and required an average 26.5 days hospitalization. DRGs allowed only 15% extra reimbursement for these complex cases. High-risk, referred surgical patients are much sicker than they appear to the DRG system, and in all 100 cases compensation was grossly inadequate.