TY - JOUR
T1 - Age and mortality after injury
T2 - is the association linear?
AU - Friese, R. S.
AU - Wynne, J.
AU - Joseph, B.
AU - Hashmi, A.
AU - Diven, C.
AU - Pandit, V.
AU - OKeeffe, Terence
AU - Zangbar, B.
AU - Kulvatunyou, N.
AU - Rhee, P.
N1 - Funding Information:
Acknowledgments. This work was partially funded by the DARPA/NSIC/ Industry/University PRISM and HDSS Consortia. The authors acknowledge the technical contributions of and helpful discussions with the many researchers who participated in these consortia. One of us, L.H., wishes to acknowledge all the hard work done by the consortia members, present and past students, postdocs, and visitors to his group at Stanford University.
Publisher Copyright:
© 2014, Springer-Verlag Berlin Heidelberg.
PY - 2014/10/16
Y1 - 2014/10/16
N2 - Introduction: Multiple studies have demonstrated a linear association between advancing age and mortality after injury. An inflection point, or an age at which outcomes begin to differ, has not been previously described. We hypothesized that the relationship between age and mortality after injury is non-linear and an inflection point exists.Methods: We performed a retrospective cohort analysis at our urban level I center from 2007 through 2009. All patients aged 65 years and older with the admission diagnosis of injury were included. Non-parametric logistic regression was used to identify the functional form between mortality and age. Multivariate logistic regression was utilized to explore the association between age and mortality. Age 65 years was used as the reference. Significance was defined as p < 0.05.Conclusions: The risk of death after injury varies linearly with age until 84 years. After 84 years of age, the mortality rates decline. These findings may reflect the varying severity of comorbidities and differences in baseline functional status in elderly trauma patients. Specifically, a proportion of our injured patient population less than 84 years old may be more frail, contributing to increased mortality after trauma, whereas a larger proportion of our injured patients over 84 years old, by virtue of reaching this advanced age, may, in fact, be less frail, contributing to less risk of death.Results: A total of 1,107 patients were included in the analysis. One-third required intensive care unit (ICU) admission and 48 % had traumatic brain injury. 229 patients (20.6 %) were 84 years of age or older. The overall mortality was 7.2 %. Our model indicates that mortality is a quadratic function of age. After controlling for confounders, age is associated with mortality with a regression coefficient of 1.08 for the linear term (p = 0.02) and a regression coefficient of −0.006 for the quadratic term (p = 0.03). The model identified 84.4 years of age as the inflection point at which mortality rates begin to decline.
AB - Introduction: Multiple studies have demonstrated a linear association between advancing age and mortality after injury. An inflection point, or an age at which outcomes begin to differ, has not been previously described. We hypothesized that the relationship between age and mortality after injury is non-linear and an inflection point exists.Methods: We performed a retrospective cohort analysis at our urban level I center from 2007 through 2009. All patients aged 65 years and older with the admission diagnosis of injury were included. Non-parametric logistic regression was used to identify the functional form between mortality and age. Multivariate logistic regression was utilized to explore the association between age and mortality. Age 65 years was used as the reference. Significance was defined as p < 0.05.Conclusions: The risk of death after injury varies linearly with age until 84 years. After 84 years of age, the mortality rates decline. These findings may reflect the varying severity of comorbidities and differences in baseline functional status in elderly trauma patients. Specifically, a proportion of our injured patient population less than 84 years old may be more frail, contributing to increased mortality after trauma, whereas a larger proportion of our injured patients over 84 years old, by virtue of reaching this advanced age, may, in fact, be less frail, contributing to less risk of death.Results: A total of 1,107 patients were included in the analysis. One-third required intensive care unit (ICU) admission and 48 % had traumatic brain injury. 229 patients (20.6 %) were 84 years of age or older. The overall mortality was 7.2 %. Our model indicates that mortality is a quadratic function of age. After controlling for confounders, age is associated with mortality with a regression coefficient of 1.08 for the linear term (p = 0.02) and a regression coefficient of −0.006 for the quadratic term (p = 0.03). The model identified 84.4 years of age as the inflection point at which mortality rates begin to decline.
KW - Geriatric trauma
KW - Intensive care unit admission and old age
KW - Old age and mortality
KW - Outcome is elderly trauma patients
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U2 - 10.1007/s00068-014-0380-0
DO - 10.1007/s00068-014-0380-0
M3 - Article
AN - SCOPUS:84919868713
SN - 1863-9933
VL - 40
SP - 567
EP - 572
JO - European Journal of Trauma and Emergency Surgery
JF - European Journal of Trauma and Emergency Surgery
IS - 5
ER -