A novel long-term quality metric for endovascular abdominal aortic aneurysm repair, wins above average, discriminates...

Endovascular abdominal aortic aneurysm repair (EVAR) has low perioperative morbidity and mortality, thereby making long-term outcomes the primary determinant of overall quality. Our aim was to develop a novel, long-term EVAR quality metric capable of discriminating center performance and predicting future outcomes, using previously developed earned-outcomes methods.

Vascular Quality Initiative-Medicare-linked data were used to examine elective EVAR (2010-2015, with follow-up to 2019). Centers were evaluated based on the primary outcome: a composite of mortality, major reintervention, or aneurysm rupture. Major reintervention was defined as any EVAR-related reintervention that met one of the following criteria: (1) open surgical reintervention, (2) more than two nights of hospital admission for reintervention, or (3) excessive endovascular reintervention burden (three or more reinterventions). Using methods similar to those used in sports analytics, cumulative, probability-based metrics (wins above average, WAA) were calculated to generate risk-adjusted, volume-sensitive center-level rankings based on the primary outcome. Risk adjustment used Cox proportional hazards modeling. Patient and center characteristics and outcomes were compared across center quality quartiles (Q1, lowest quality quartile through Q4, highest quality quartile). The ability of 2010 to 2015 quality quartiles to predict outcomes in a future period (2016-2017) was determined.

From 2010 to 2015, the analysis included 10,081 patients treated at 198 centers. WAA quartiles effectively discriminated 4-year composite outcomes of mortality, aneurysm rupture, or major reintervention: Q1 44.5% vs Q2 40.4% vs Q3 34.0% vs Q4 28.8% (P < .001). Quartiles also demonstrated differences in each primary outcome component: mortality (Q1 38% vs Q2 35% vs Q3 28% vs Q4 24%; P < .001), major reintervention (Q1 13% vs Q2 11% vs Q3 8.5% vs Q4 7.8%; P < .001), and aneurysm rupture (Q1 3.6% vs Q2 2.0% vs Q3 1.5% vs Q4 1.8%; P < .001). In 2016 to 2017, 5153 patients underwent EVAR at centers where quality quartiles had been defined from the preceding study period. Two-year rates of composite mortality, aneurysm rupture, or major reintervention confirmed the predictive value of WAA quartiles: Q1 22.8% vs Q2 21.0% vs Q3 19.6% vs Q4 17.0% (P = .002).

WAA is a novel, long-term EVAR quality metric that evaluates aggregate aorta-related outcomes and effectively differentiates center-level performance. This innovative approach has potential applications in quality improvement initiatives and benchmarking of EVAR care delivery.