SPINAL
CORD INJURY
Incidence: It is estimated that the annual incidence of
spinal cord injury (SCI), not including those who die at the scene of the accident, is
approximately 40 cases per million population in the U. S., or approximately 10,000 new
cases each year. Since there have not been any overall incidence studies of SCI in the
U.S. since the 1970' it is not known if incidence has changed in recent years.
Prevalence: The number of people in the United States
who are alive today and who have SCI has been estimated to be between 721 and 906 per
million population. This corresponds to between 183,000 and 230,000 persons. Note: Incidence and prevalence statistics are estimates obtained from several
studies. These statistics are not derived from the National SCI Database.
The National Spinal Cord Injury Database has been in existence since 1973 and
captures data from an estimated 13% of new SCI cases in the U.S. Since its inception, 24
federally funded Model SCI Care Systems have contributed data to the National SCI
Database. As of September, 1999 the database contained information on more than 19,648
persons who sustained traumatic spinal cord injuries. All the remaining statistics on this
sheet are derived from this database or from collaborative studies conducted by the Model
Systems.
Detailed discussions of all topics on this sheet may be found in a special issue of the
journal, Archives of Physical Medicine and Rehabilitation, published in November,
1999.
Age at injury: SCI primarily affects young adults.
Fifty-five percent of SCIs occur among persons in the 16 to 30 year age group, and the
average age at injury is 31.8 years. Since 1973 there has been an increase in the mean age
at time of injury. Those who were injured before 1979 had a mean age of 28.6 while those
injured after 1990 had a mean age of 35.1 years. Another trend is an increase in the
proportion of those who were at least 61 years of age at injury. In the 1970' persons
older than 60 years of age at injury comprised 4.7% of the database. Since 1990 this has
increased to 10%. This trend is not surprising since the median age of the general
population has increased from 27.9 years to 33.1 years during the same time period.
Gender: Overall, 81.7% of all persons in the national
database are male. Although this four-to-one male to female ratio has varied little
throughout the 25 years of the Model Systems data collection, since 1990, the percentage
of males has decreased to 80.6% (from 81.8% in the 1970').
Ethnic groups: A significant trend over time has been
observed in the racial distribution of persons in the Model System database. Among persons
injured between 1973 and 1978, 77.5% of persons in the database were Caucasian, 13.5% were
African-American, 5.7% were Hispanic, 2% were American Indian and 0.8% were Asian.
However, among those injured since 1990 only 58.1% were Caucasian, while 28% were
African-American, 8.4% were Hispanic, 0.4% were American Indian, 2.1% were Asian (and 0.4%
were unknown).
Etiology: Since 1990, motor vehicle crashes account for
37.4% of the SCI cases reported. The next largest contributor is acts of violence
(primarily gunshot wounds), followed by falls and recreational sporting activities.
Interesting trends in the database show the proportions of injuries due to motor vehicle
crashes and sporting activities have declined while the proportion of injuries from acts
of violence and falls has increased steadily since 1973. The graph shows the percentage
breakdown of causes.
Neurologic level and extent of lesion: Persons with
tetraplegia (51.7%) have sustained injuries to one of the eight cervical segments of the
spinal cord; those with paraplegia (46.7%) have lesions in the thoracic, lumbar, or sacral
regions of the spinal cord. For the remaining persons, 0.7% recover prior to discharge and
0.7% and 1% are persons for whom this information is not available.
Since 1990 the most frequent
neurologic category is incomplete tetraplegia (29.5%), followed by complete paraplegia
(27.9%), incomplete paraplegia (21.3%), and complete tetraplegia (18.5%). Trends over time
indicate an increasing proportion of persons with incomplete paraplegia and a decreasing
proportion of persons with complete tetraplegia.
Occupational status: More than half (60.5%) of those
persons with SCI admitted to a Model System reported being employed at the time of their
injury. The post-injury employment picture is better among persons with paraplegia than
among their tetraplegic counterparts. By post-injury year 10, 35.3% of persons with
paraplegia are employed, while 24.3% of those with tetraplegia are employed during the
same year.
Residence: Today 91.3% of all persons with SCI who are
discharged alive from the system are sent to a private, noninstitutional residence (in
most cases their homes before injury.) Only 4.8% are discharged to nursing homes. The
remaining are discharged to hospitals, group living situations or other destinations.
Marital status: Considering the youthful age of most
persons with SCI, it is not surprising that most (53.5%) are single when injured. Among
those who were married at the time of injury, as well as those who marry after injury, the
likelihood of their marriage remaining intact is slightly lower when compared to the
uninjured population. The likelihood of getting married after injury is also reduced.
Length of stay: Overall, average days hospitalized in the
acute care unit for those who enter a Model System immediately following injury has
declined from 26 days in 1974 to 15 days in 1998. Similar downward trends are noted for
days in the rehab unit, from 115 days to 44 days. Overall, mean days hospitalized (during
acute care and rehab) were greater for persons with neurologically complete injuries.
Lifetime costs: Average yearly health care and living
expenses and the estimated lifetime costs that are directly attributable to SCI vary
greatly according to severity of injury:
Average Yearly Expenses
(in 1998 dollars
| Severity of Injury |
First Year |
Each Subsequent Year |
| High Tetraplegia (C1-C4) |
$529,675 |
$94,878 |
| Low Tetraplegia (C5-C8) |
$342,041 |
$38,865 |
| Paraplegia |
$193,543 |
$19,694 |
| Incomplete Motor Functional at any Level |
$156,101 |
$10,940 |
| All Groups |
$251,885 |
$30,676 |
Estimated lifetime costs by Age at Injury
(discounted at 4%)
| Severity of Injury |
25 years old |
50 years old |
| High Tetraplegia (C1-C4) |
$1,713,267 |
$1,112,884 |
| Low Tetraplegia (C5-C8) |
$950,257 |
$670,587 |
| Paraplegia |
$543,221 |
$414,365 |
| Incomplete Motor Functional at any Level |
$364,491 |
$293,393 |
These figures do not include any indirect costs such as losses in wages, fringe benefits
and productivity which could average almost $46,000 but vary substantially based on
education, severity of injury and pre-injury employment history.
Life expectancy is the average remaining years of life
for an individual. Life expectancies for persons with SCI continue to increase, but are
still somewhat below life expectancies for those with no spinal cord injury. Mortality
rates are significantly higher during the first year after injury than during subsequent
years, particularly for severely injured persons.
Life Expectancy for Persons who survive the first 24 hours
| Age at Injury |
No SCI |
Motor Functional at any Level |
Para |
Low Tetra (C5-C8) |
High Tetra (C1-C4) |
Ventilator Dependent
at any Level |
| 20 yrs |
57.2 |
51.6 |
45.2 |
39.4 |
33.8 |
16.2 |
| 40 yrs |
38.4 |
33.5 |
27.8 |
23.0 |
18.7 |
7.2 |
| 60 yrs |
21.2 |
17.5 |
13.0 |
9.6 |
6.8 |
1.2 |
Life Expectancy for Persons who survive at least 1 year post-injury
| Age at Injury |
No SCl |
Motor Functional at any Level |
Para |
Low Tetra (C5-C8) |
High Tetra (C1-C4) |
Ventilator Dependent
at any Level |
| 20 yrs |
57.2 |
52.5 |
46.2 |
41.2 |
37.1 |
26.8 |
| 40 yrs |
38.4 |
34.3 |
28.7 |
24.5 |
21.2 |
13.7 |
| 60 yrs |
21.2 |
18.1 |
13.7 |
10.6 |
8.4 |
4.0 |
Cause of death: In years past, the leading cause of death
among persons with SCI was renal failure. Today, however, significant advances in urologic
management have resulted in dramatic shifts in the leading causes of death. Persons
enrolled in the National SCI Database since its inception in 1973 have now been followed
for 26 years after injury. During that time, the causes of death that appear to have the
greatest impact on reduced life expectancy for this population are pneumonia, pulmonary
emboli and septicemia.
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