Our country is notoriously difficult for epidemiological research because of its diversity not only culturally and socioeconomically, but also in healthcare and the ability to track diagnoses.
In an attempt to conduct an epidemiological study of spinal cord injury within a closed system, a recent study used the US military to describe the risk factors for spinal cord injury. The military represents a diverse demographic that is not affected by state-to-state differences of economy or healthcare.
Their major findings were that being male, white, and between the ages of 20 and 39 represented the most significant risk factors for spinal cord injury. In addition, the study found that lower ranking military were also at higher risk, which may reflect socioeconomic differences. Some of the limitations of the study are obvious-women and older adults are misrepresented in the military. However, the study only represented injuries sustained during the course of service and not during combat, and therefore does have usefulness as a representation of civilian spinal cord injury in the US.
Schoenfeld AJ, McCriskin B, Hsaio M, & Burks R. Incidence and epidemiology of spinal cord injury within a closed American population: The United States military (2000-2009). Spinal Cord. (September 2011).