The Association Between ABO Blood Type and Mortality Among Severely Injured Trauma Patients

BACKGROUND

Prior research has reported an association among trauma patients between blood type O and adverse events. More recently, another study reported that severely injured trauma patients of mostly O Rh positive blood type were more likely to die.

OBJECTIVE

The objective of the current study is to examine whether the same increased association is observed for blood type O severely injured patients in a more generalizable population comprised of Rh positive and Rh negative individuals.

METHODS

Patients admitted to a Level-I academic trauma center between 2015 and 2018 with severe injury (Injury Severity Score >15) were included in this retrospective cohort study. Logistic regression estimated odds ratios (ORs) and 95% confidence intervals (CIs) for the association between blood type and mortality.

RESULTS

Among 3,913 patients, a majority were either blood type O (47.5%) or A (34.7%) and 60% were Rh positive. There was no observed difference in complication rates by blood type, and there was no observed significant association with death overall or by cause of death. There were weak, increased associations for blood type B (OR 1.61, 95% CI 0.74-3.53) and type O (OR 1.57, 95% CI 0.90-2.76) compared with blood type A patients.

CONCLUSION

Contrary to prior research, the current results suggest no association between blood type and mortality among severely injured trauma patients.

A decompositional analysis of firearm-related mortality in the United States, 2001-2012

Prior literature reporting increased rates of firearm-related homicide and suicide with increasing firearm availability is limited by only examining the availability of firearms, which is only one component of firearm-related mortality. The objective of the current study is to separate the rates into their respective components and determine which components contribute to mortality rate changes. To address the objective, nationally representative data from 2001 to 2012 was collected from a variety of publicly-available sources. Utilizing decompositional methodology, a negative binomial regression was used to estimate rate ratios for the association between the components and year category, and relative contributions of each component were calculated. From 2001 to 2012, the homicide and unintentional mortality rate decreased while the suicide rate increased. The suicide rate was only the firearm prevalence rate. The unintentional mortality rate was a factor of firearm prevalence, injury incidence, and case fatality rate. The homicide rate was a factor of firearm prevalence, violent crime rate, injury incidence, and case fatality rate. The current results suggest that the contributors of changes in firearm-related mortality are multi-faceted. Future studies should perform a decompositional analysis utilizing more granular data to examine whether the currently reported results are true associations or a factor of ecologic fallacy.