Retrospective analysis of nationally representative data collected for the National Hospital Discharge Survey.
To compare the performance of the Charlson and Elixhauser comorbidity-based measures for predicting in-hospital mortality after cervical spine fractures.
Mortality occurring as a consequence of cervical spine fractures is very high in the elderly. The Charlson comorbidity measure has been associated with an increased risk of mortality, but its predictive accuracy has yet to be compared with the more recent and increasingly used Elixhauser measure.
Using the National Hospital Discharge Survey for the years 1990 through 2007, we identified all patients aged 65 years or older hospitalized with a diagnosis of cervical spine fracture. The association of each Charlson and Elixhauser comorbidity with mortality was assessed in bivariate analysis using χ2 tests. Two main multivariable logistic regression models were constructed, with in-hospital mortality as the dependent variable and 1 of the 2 comorbidity-based measures (as well as age, sex, and year of admission) as independent variables. A base model that included only age, sex, and year of admission was also evaluated. The discriminative ability of the models was quantified using the area under the receiver operating characteristic curve (AUC).
Among an estimated 111,564 patients admitted for cervical spine fractures, 7.6% died in the hospital. Elixhauser comorbidity adjustment provided better prediction of in-hospital case mortality (AUC = 0.852, 95% confidence interval: 0.848–0.856) than the Charlson model (AUC = 0.823, 95% confidence interval: 0.819–0.828) and the base model with no comorbidities (AUC = 0.785, 95% confidence interval: 0.781–0.790). In terms of relative improvement in predictive ability, the Elixhauser model performed 43% better than the Charlson model.
The Elixhauser comorbidity risk adjustment method performed numerically better than the widely used Charlson measure in predicting in-hospital mortality after cervical spine fractures.
Level of Evidence: N/A
We assessed and compared the discriminative ability of the Charlson and Elixhauser comorbidity measures for predicting in-hospital mortality in elderly patients admitted with cervical spine fractures. The Elixhauser comorbidity risk adjustment method performed numerically better than the widely used Charlson measure in predicting inpatient death after cervical spine fractures.
*Orthopaedic Hand and Upper Extremity Service, Massachusetts General Hospital, Boston, MA
†Department of Orthopaedic Surgery, Brigham and Women's Hospital, Boston, MA; and
‡Orthopaedic Spine Service, Yawkey Center, Massachusetts General Hospital, Boston, MA.
Address correspondence and reprint requests to Thomas D. Cha, MD, MBA, Orthopaedic Spine Service, Yawkey Center, Ste 3A, Massachusetts General Hospital, 55 Fruit St, Boston, MA 02114; E-mail: firstname.lastname@example.org
Acknowledgment date: July 21, 2014. First revision date: December 1, 2014. Second Revision date: January 20, 2015. Acceptance date: January 20, 2015.
The manuscript submitted does not contain information about medical device(s)/drug(s).
No funds were received in support of this work.
Relevant financial activities outside the submitted work: board membership, grants, consultancy, expert testimony, royalties, stocks, other (Deputy Editor Journal of Hand Surgery, Deputy Editor for CORR, institutional fellowship support).