Incidence and epidemiology of spinal cord injury within a closed American population: the United States military (2000-2009).

STUDY DESIGN

Cohort study.

OBJECTIVES

The objective of this study was to characterize the incidence of spinal cord injury (SCI) within the population of the United States military from 2000-2009. This investigation also sought to define potential risk factors for the development of SCI.

SETTING

The population of the United States military from 2000-2009.

METHODS

The Defense Medical Epidemiology Database was queried for the years 2000-2009 using the International Classification of Diseases, Ninth Revision, Clinical Modification codes for SCI (806.0, 806.1, 806.2, 806.3, 806.4, 806.5, 806.8, 806.9, 952.0, 952.1, 952.2, 952.8, 952.9). The raw incidence of SCI was calculated and unadjusted incidence rates were generated for the risk factors of age, sex, race, military rank and branch of service. Adjusted incidence rate ratios were subsequently determined via multivariate Poisson regression analysis that controlled for other factors in the model and identified significant independent risk factors for SCI.

RESULTS

Between 2000 and 2009, there were 5928 cases of SCI among a population at-risk of 13,813,333. The raw incidence of SCI within the population was 429 per million person-years. Male sex, white race, enlisted personnel and service in the Army, Navy or Marine Corps were found to be significant independent risk factors for SCI. The age groups 20-24, 25-29 and >40 were also found to be at significantly greater risk of developing the condition.

CONCLUSIONS

This study is one of the few investigations to characterize the incidence, epidemiology and risk factors for SCI within the United States. Results presented here may represent the best-available evidence for risk factors of SCI in a large and diverse American cohort.