Browsing by Author "Hemmila, Mark R."

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    Comparison of a Trauma Comorbidity Index with Other Measures of Comorbidities to Estimate Risk of Trauma Mortality
    (Wiley Online Library, 2021-04-29) Jenkins, Peter C.; Dixon, Brian E.; Savage, Stephanie A.; Carroll, Aaron E.; Newgard, Craig D.; Tignanelli, Christopher J.; Hemmila, Mark R.; Timsina, Lava; Surgery, School of Medicine
    Background Comorbidities influence the outcomes of injured patients, yet a lack of consensus exists regarding how to quantify that association. This study details the development and internal validation of a trauma comorbidity index (TCI) designed for use with trauma registry data and compares its performance to other existing measures to estimate the association between comorbidities and mortality. Methods Indiana state trauma registry data (2013-2015) was used to compare the TCI with the Charlson and Elixhauser comorbidity indices, a count of comorbidities, and comorbidities as separate variables. The TCI approach utilized a randomly selected training cohort and was internally validated in a distinct testing cohort. The C-statistic of the adjusted models was tested using each comorbidity measure in the testing cohort to assess model discrimination. C-statistics were compared using a Wald test, and stratified analyses were performed based on predicted risk of mortality. Multiple imputation was used to address missing data. Results The study included 84,903 patients (50% each in training and testing cohorts). The Indiana TCI model demonstrated no significant difference between testing and training cohorts (p = 0.33). It produced a C-statistic of 0.924 in the testing cohort, which was significantly greater than that of models using the other indices (p < 0.05). The C-statistics of models using the Indiana TCI and the inclusion of comorbidities as separate variables – the method used by the American College of Surgeons Trauma Quality Improvement Program – were comparable (p = 0.11) but use of the TCI approach reduced the number of comorbidity-related variables in the mortality model from 19 to one. Conclusions When examining trauma mortality, the TCI approach using Indiana state trauma registry data demonstrated superior model discrimination and/or parsimony compared to other measures of comorbidities.
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    Factors associated with optimal patient outcomes after operative repair of isolated hip fractures in the elderly
    (BMJ, 2020-12-22) deMeireles, Alirio J.; Gerhardinger, Laura; Oliphant, Bryant W.; Jenkins, Peter C.; Cain-Nielsen, Anne H.; Scott, John W.; Hemmila, Mark R.; Sangji, Naveen F.; Surgery, School of Medicine
    Background: Increased time to operative intervention is associated with a greater risk of mortality and complications in adults with a hip fracture. This study sought to determine factors associated with timeliness of operation in elderly patients presenting with an isolated hip fracture and the influence of surgical delay on outcomes. Methods: Trauma quality collaborative data (July 2016 to June 2019) were analyzed. Inclusion criteria were patients ≥65 years with an injury mechanism of fall, Abbreviated Injury Scale (AIS) 2005 diagnosis of hip fracture, and AIS extremity ≤3. Exclusion criteria included AIS in other body regions >1 and non-operative management. We examined the association of demographic, hospital, injury presentation, and comorbidity factors on a surgical delay >48 hours and patient outcomes using multivariable regression analysis. Results: 10 182 patients fit our study criteria out of 212 620 patients. Mean age was 82.7±8.6 years and 68.7% were female. Delay in operation >48 hours occurred in 965 (9.5%) of patients. Factors that significantly increased mortality or discharge to hospice were increased age, male gender, emergency department hypotension, functionally dependent health status (FDHS), advanced directive, liver disease, angina, and congestive heart failure (CHF). Delay >48 hours was associated with increased mortality or discharge to hospice (OR 1.52; 95% CI 1.13 to 2.06; p<0.01). Trauma center verification level, admission service, and hip fracture volume were not associated with mortality or discharge to hospice. Factors associated with operative delay >48 hours were male gender, FDHS, CHF, chronic renal failure, and advanced directive. Admission to the orthopedic surgery service was associated with less incidence of delay >48 hours (OR 0.43; 95% CI 0.29 to 0.64; p<0.001). Discussion: Hospital verification level, admission service, and patient volume did not impact the outcome of mortality/discharge to hospice. Delay to operation >48 hours was associated with increased mortality. The only measured modifiable characteristic that reduced delay to operative intervention was admission to the orthopedic surgery service. Level of evidence: III.