Outcomes after Lower-Extremity Reconstruction in DRGs 478 and 479

Abstract

Purpose. To assess outcomes for 21,261 patients in DRGs 478 and 479 hospitalized in Veterans Affairs Medical Centers (VAMCs) during fiscal years 1991–1994. DRGs 478 and 479 contain patients undergoing a variety of vascular procedures including lower-extremity arterial reconstruction.Methods. VA Patient Treatment File (PTF) data were analyzed using Patient Management Category (PMC) software which defined illness severity, patient complexity as defined by PMC count, and calculated resource intensity scale (RIS), a measure of resource utilization, for each admission.Results. In-hospital mortality rate was 3.16% (671/21,261) for all patients. Mortality did not differ between the 14,155 patients who underwent extremity arterial reconstruction (3.22%) and the remaining patients (3.03%). The incidence of ICD-9-CM-coded complications was 20.4% after limb revascularization versus 12.8% for remaining patients (P < 0.001). Length of stay (LOS) was 18.6 ± 17.6 days with versus 10.3 ± 14.5 days without limb revascularization (P < 0.001). As defined in this study, patients who underwent limb revascularization were older (64.1 ± 9.6 vs 62.2 ± 11.0, P < 0.001); had higher illness severity scores (3.63 ± 1.60 vs 2.72 ± 1.72, P < 0.001); were more complex (had higher PMC count: 2.59 ± 1.35 vs 2.54 ± 1.34, P = 0.016); and required utilization of more resources (had higher RIS: 2.16 ± 0.81 vs 1.68 ± 0.76, P < 0.001) than remaining patients. Logistic regression analysis limited to those undergoing extremity revascularization revealed that age, presence of complications, patient complexity, illness severity, and acute arterial thromboembolism were increasingly and independently associated with greater in-hospital mortality. The logistic regression model also showed that the type of arterial reconstruction was related to in-hospital mortality: arterial bypass (ICD-9-CM 39.29) was associated with lower mortality. Outcomes were defined for the subgroup (n = 7728) undergoing arterial bypass (ICD-9-CM 39.29) who were assigned to Patient Management Category 4101, 4113, or 4141: Mortality rates were 2.26, 2.19, and 5.03% for those undergoing elective bypass (n = 3003), urgent bypass (n = 3513), and bypass for gangrene (n = 1212), respectively. Octogenarians did not experience higher mortality rates after elective bypass [1.4% (1/73) vs 2.3% (67/2930), n.s.], but experienced higher mortality rates after urgent bypass [8.6% (8/93) vs 2.0% (69/3420), P < 0.001] and after bypass for gangrene [11.6% (5/43) vs 4.8% (56/1169), P < 0.045].Conclusions. Outcomes for patients in DRGs 478 and 479 who underwent extremity revascularization differed from those who did not. Outcomes varied by the type of arterial reconstruction and its urgency and indication and within selected subpopulations (i.e., octogenarians). DRG-based reimbursement would not be sensitive to these clinically important factors which have a major impact on outcomes and resource utilization.