Background: The Trauma Quality Improvement Project (TQIP) uses an injury prediction model for performance benchmarking. We hypothesize that at a Level I high-volume penetrating trauma center, performance outcomes will be biased due to inclusion of patients with nonsurvivable injuries.
Methods: Retrospective chart review was conducted for all patients included in the institutional TQIP analysis from 2013 to 2014 with length of stay (LOS) less than 1 day to determine survivability of the injuries. Observed (O)/expected (E) mortality ratios were calculated before and after exclusion of these patients. Completeness of data reported to TQIP was examined.
Results: Eight hundred twenty-six patients were reported to TQIP including 119 deaths. Nonsurvivable injuries accounted 90.9% of the deaths in patients with an LOS of 1 day or less. The O/E mortality ratio for all patients was 1.061, and the O/E ratio after excluding all patients with LOS less than 1 day found to have nonsurvivable injuries was 0.895. Data for key variables were missing in 63.3% of patients who died in the emergency department, 50% of those taken to the operating room and 0% of those admitted to the intensive care unit. Charts for patients who died with LOS less than 1 day were significantly more likely than those who lived to be missing crucial.
Conclusion: This study shows TQIP inclusion of patients with nonsurvivable injuries biases outcomes at an urban trauma center. Missing data results in imputation of values, increasing inaccuracy. Further investigation is needed to determine if these findings exist at other institutions, and whether the current TQIP model needs revision to accurately identify and exclude patients with nonsurvivable injuries.
Level of evidence: Prognostic and epidemiological, level III.