Behavioral Risk Factors of Mortality After Spinal Cord Injury
Abstract
Krause JS, Carter RE, Pickelsimer E. Behavioral risk factors of mortality after spinal cord injury.
Objective
To test hypothesized relationships between multiple behavioral indicators and mortality among persons with spinal cord injury (SCI), while controlling for biographic and injury characteristics.
Design
Prospective cohort study with behavioral data collected by mailed survey in late 1997 and early 1998. Mortality status was ascertained as of December 31, 2005.
Setting
A large rehabilitation hospital in the southeastern United States.
Participants
Adults (N=1386) with traumatic SCI, at least 1 year postinjury.
Interventions
Not applicable.
Main Outcome Measures
Primary outcome was time from survey to mortality or censoring. Mortality status was determined using the National Death Index and the Social Security Death Index. There were 224 deaths (16.2%) in the full sample, and due to missing data, 188 deaths were observed in the 1251 participants included in the final statistical model.
Results
Cox proportional hazards modeling identified several significant behavioral predictors of mortality. In the first set of analyses, the significance of a single behavioral variable was assessed while controlling for biographic and injury predictors. We subsequently built a comprehensive model based on an optimal group of behaviors. The best set of behavioral predictors included: smoking, binge drinking (number of episodes with 5 or more drinks), prescription medication use, and number of hours out of bed per day. Inclusion of these variables improved prediction of survival compared with biographic and injury variables alone, as the pseudo-R2 increased from .121 to .164 and the concordance from .730 to .769.
Conclusions
The results affirm the importance of avoiding basic risk behaviors, such as smoking and alcohol misuse, and affirm their importance as targets of intervention in association with SCI rehabilitation.
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, Dept of Health Sciences and Research, College of Health Professions, Medical University of South Carolina, 77 President St, Ste 117, PO Box 250700, Charleston, SC 29425
Supported by the National Institute for Disability and Rehabilitation Research (grant no. H133G030117), the Model Spinal Cord Injury Systems (grant no. H133N000005), and the National Institutes of Health (grant no. 1R01 NS 48117-01 A1). 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