Risk of Mortality After Spinal Cord Injury: An 8-Year Prospective Study
Abstract
Krause JS, Zhai Y, Saunders LL, Carter RE. Risk of mortality after spinal cord injury: an 8-year prospective study.
Objective
To evaluate a theoretical model for mortality after spinal cord injury (SCI) by sequentially analyzing 4 sets of risk factors in relation to mortality (ie, adding 1 set of factors to the regression equation at a time).
Design
Prospective cohort study of data collected in late 1997 and early 1998 with mortality status ascertained in December 2005. We evaluated the significance of 4 successive sets of predictors (biographic and injury, psychologic and environmental, behavioral, health and secondary conditions) using Cox proportional hazards modeling and built a full model based on the optimal predictors.
Setting
A specialty hospital.
Participants
Adults (N=1386) with traumatic SCI, at least 1 year postinjury, participated. There were 224 deaths. After eliminating cases with missing data, there were 1209 participants, with 179 deceased at follow-up.
Interventions
Not applicable.
Main Outcome Measures
Mortality status was determined using the National Death Index and the Social Security Death Index.
Results
The final model included 1 environmental variable (poverty), 2 behavioral factors (prescription medication use, binge drinking), and 4 health factors or secondary conditions (hospitalizations, fractures/amputations, surgeries for pressure ulcers, probable major depression).
Conclusions
The results supported the major premise of the theoretical model that risk factors are more important the more proximal they are in a theoretical chain of events leading to mortality. According to this model, mortality results from declining health, precipitated by high-risk behaviors. These findings may be used to target those who are at high risk for early mortality as well as to direct interventions to the particular risk factor.
aCollege of Health Professions, Medical University of South Carolina, Charleston, SC
bDepartment of Biostatistics, Bioinformatics, and Epidemiology, Medical University of South Carolina, Charleston, SC
Correspondence to James S. Krause, PhD, Department of Health Sciences and Research, College of Health Professions, Medical University of South Carolina, 77 President St, Suite 117, MSC 700, Charleston, SC 29425
Supported by a field-initiated grant from the National Institute for Disability and Rehabilitation Research (grant no. H133G030117) and the Model Spinal Cord Injury Systems (H133N000005), and funding from the National Institutes of Health (grant no. 1R01 NS 48117). The opinions here are those of the grantee and do not necessarily reflect those of the funding agencies.
No commercial party having a direct financial interest in the results of the research supporting this article has or will confer a benefit on the authors or on any organization with which the authors are associated.
ABSTRACT