Does Adding a Measure of Social Vulnerability to a Surgical Risk Calculator Improve Its Performance?

BACKGROUND: Emerging literature suggests that measures of social vulnerability should be incorporated into surgical risk calculators. The Social Vulnerability Index (SVI) is a measure designed by the CDC that encompasses 15 socioeconomic and demographic variables at the census tract level. We examined whether adding the SVI into a parsimonious surgical risk calculator would improve model performance. STUDY DESIGN: The eight-variable Surgical Risk Preoperative Assessment System (SURPAS), developed using the entire American College of Surgeons (ACS) NSQIP database, was applied to local ACS-NSQIP data from 2012 to 2018 to predict 12 postoperative outcomes. Patient addresses were geocoded and used to estimate the SVI, which was then added to the model as a ninth predictor variable. Brier scores and c-indices were compared for the models with and without the SVI. RESULTS: The analysis included 31,222 patients from five hospitals. Brier scores were identical for eight outcomes and improved by only one to two points in the fourth decimal place for four outcomes with addition of the SVI. Similarly, c-indices were not significantly different (p values ranged from 0.15 to 0.96). Of note, the SVI was associated with most of the eight SURPAS predictor variables, suggesting that SURPAS may already indirectly capture this important risk factor. CONCLUSION: The eight-variable SURPAS prediction model was not significantly improved by adding the SVI, showing that this parsimonious tool functions well without including a measure of social vulnerability.

Effect of Pre-Hospital Use of the Assessment of Blood Consumption Score and Pre-Thawed Fresh Frozen Plasma on Resuscitation and Trauma Mortality.

BACKGROUND: Early blood product resuscitation reduces trauma patient mortality from hemorrhage. This mortality benefit depends on a system that can rapidly identify actively bleeding patients, initiate massive transfusion protocol (MTP), and mobilize resources to the bedside. We hypothesized that process improvement efforts that identify patients early and mobilize appropriate blood products to the bedside for immediate use would improve mortality. STUDY DESIGN: Pre-implementation, MTP activation was at the discretion of the trauma surgeon, and only PRBCs were immediately available. In June 2016, the Assessment of Blood Consumption (ABC) score was incorporated in our pre-hospital triage process, and a process for thawed plasma to be available was developed. We performed a retrospective review of patients who were hypotensive on arrival or had MTP activated. We compared mortality and MTP component ratios 15 months pre- vs 15 months post-implementation. RESULTS: Activations of MTP increased 6-fold, while the specificity of the process remained the same. In patients receiving MTP, appropriate blood product transfusion ratios increased 44%. Overall and penetrating trauma mortality improved by 23% and 41%, respectively. When divided by the Injury Severity Score (ISS), penetrating trauma mortality decreased by 65% for the ISS subgroup 15 to 24 and by 38% for ISS subgroup ≥ 25. Length of stay, ICU length of stay, and readmission rates were not significantly different. CONCLUSIONS: Delivery of balanced blood product resuscitation is essential to confer mortality benefits. Process improvement directed at early recognition of the hemorrhagic patient, immediate product availability, and product delivery to the bedside for transfusion allows for mortality reduction without increased resource use.