Quality assessment in high-acuity surgery: volume and mortality are not enough

HYPOTHESIS: A new quality assessment model for high-acuity surgery links process improvements with hospital costs and patient-centered outcomes and accurately reflects the clinical and economic impact of variance in patient acuity at the level of the practice and health care professional. DESIGN: Retrospective case series and cost analysis. SETTING: University tertiary care referral center. PATIENTS: A total of 296 patients undergoing elective pancreatic resection in 5 years. MAIN OUTCOME MEASURES: Expected preoperative morbidity (evaluated using POSSUM [Physiologic and Operative Severity Score for the Enumeration of Mortality and Morbidity]) was compared with observed morbidity (according to the Clavien complication scheme) and was correlated with total hospital costs per patient. RESULTS: As volume increased annually, patient acuity (expected morbidity) rose and complications declined. Overall, observed and expected morbidity rates were equal (54.1% vs 55.1%), for an observed-expected ratio of 0.98. Process improvement measures contributed to a steady decrease in the observed-expected morbidity ratio from 1.34 to 0.81 during the 5-year period. This decrease was strongly associated with significant cost savings as total costs per patient declined annually (from $31 541 to $18 829). This performance assessment model predicts that a 0.10 decrease in the observed-expected morbidity ratio equates to a $2549 cost savings per patient in our practice. CONCLUSIONS: Despite increasing patient acuity, better clinical and economic outcomes were achieved across time. Approaches that mitigate the impact of preoperative risk can effectively deliver quality improvement, as illustrated by a reduced observed-expected morbidity ratio. This approach is valuable in analyzing performance and process improvements and can be used to assess intrapractice and interpractice variations in high-acuity surgery.