Early Cognitive Status and Productivity Outcome After
Traumatic Brain Injury: Findings From the
TBI Model Systems
Mark Sherer, PhD, Angelle M. Sander, PhD, Todd G. Nick, PhD, Walter M. High Jr, PhD,
James F. Malec, PhD, Mitchell Rosenthal, PhD
ABSTRACT. Sherer M, Sander AM, Nick TG, High WM Jr,
Malec JF, Rosenthal M. Early cognitive status and productivity
outcome after traumatic brain injury: findings from the TBI
Model Systems. Arch Phys Med Rehabil 2002;83:183-92.
Objective: To evaluate the contribution of early cognitive
assessment to the prediction of productivity outcome after
traumatic brain injury (TBI) adjusted for severity of injury,
demographic factors, and preinjury employment status.
Design: Inception cohort.
Setting: Six inpatient brain injury rehabilitation programs.
Participants: A total of 388 adults with TBI whose post-
traumatic amnesia (PTA) resolved before discharge from inpa-
tient rehabilitation.
Interventions: Administered neuropsychologic tests during
inpatient stay on emergence from PTA. Follow-up interview
and evaluation. Predictor measures also determined.
Main Outcome Measure: Productivity status at follow-up
12 months postinjury.
Results: Multiple logistic regression analysis revealed that
preinjury productivity status, duration of PTA, education level,
and early cognitive status each made significant, independent
contributions to the prediction of productivity status at follow-
up. When adjusted for all other predictors, persons scoring at
the 75th percentile on early cognitive status (less impaired) had
1.61 times greater odds (95% confidence interval [CI], 1.07–
2.41) of being productive follow-up than those scoring at the
25th percentile (more impaired). Without adjustment, persons
scoring at the 75th percentile had 2.46 times greater odds (95%
CI, 1.77–3.43) of being productive at follow-up.
Conclusions: Findings support the utility of early cognitive
assessment by using neuropsychologic tests. In addition to
other benefits, early cognitive assessment makes an indepen-
dent contribution to prediction of late outcome. Findings sup-
port the clinical practice of performing initial neuropsychologic
evaluations after resolution of PTA.
Key Words: Brain injuries; Cognition disorders; Employ-
ment; Neuropsychological tests; Rehabilitation; Treatment out-
come.
© 2002 by the American Congress of Rehabilitation Medi-
cine and the American Academy of Physical Medicine and
Rehabilitation
T
RAUMATIC BRAIN INJURY (TBI) can cause a variety
of physical, cognitive, behavioral, and emotional impair-
ments.
1
Severity and type of impairments are determined by a
number of factors, including initial severity of injury, pattern of
diffuse and focal brain lesions, time since injury, age at time
of injury, and others. Although physical impairments may be
prominent early, particularly after severe TBI, cognitive and
behavioral impairments are more persistent and make a greater
contribution to long-term handicap.
2,3
Common areas of per-
sistent cognitive impairment are speed of processing, memory,
cognitive flexibility, and problem solving.
4,5
The cognitive status of persons with TBI is often assessed
early after injury, either at a fixed time postinjury
6
or after
resolution of posttraumatic amnesia
7
(PTA). Early assessment
is important for a number of reasons. Cognitive assessments
may be used to provide feedback to the patient, family, and
health care professionals regarding the patient’s current cogni-
tive status, supervision needs, ability to understand and recall
safety precautions, capacity for driving, ability to return to
work, and many other issues. Early cognitive assessment may
be used to guide rehabilitation interventions. The initial assess-
ment provides a baseline against which later assessments may
be compared to facilitate detection of improvement or deteri-
oration. Serial cognitive assessments may be used to evaluate
the effectiveness of pharmacologic trials. Early cognitive as-
sessment may also be used to predict eventual functional out-
come.
8,9
Our review of investigations of the ability of early cognitive
assessment to contribute to prediction of later functional out-
come indicated that a number of issues remain unresolved. One
common indicator of functional outcome is employment status.
Employment is an outcome that is valued by society, and it can
be more objectively assessed than personal independence.
5
Employment outcome is a difficult outcome to predict because
it is influenced by a variety of factors not associated with the
patient’s neurologic status. Such factors include preinjury em-
ployment status, demographic variables, availability of envi-
ronmental supports, and family support.
10
Studies that have evaluated cognitive status in the postacute
period and assessed employment outcome at the same time
have generally found a positive association between cognitive
status and employment status.
11-15
Although these studies in-
dicate that cognitive status is related to employment outcome
when both are measured at the same time, they do not show
prediction of late outcome from findings obtained early after
injury.
From the Methodist Rehabilitation Center, Jackson, MS (Sherer); Departments of
Neurology, Psychiatry, and Health Sciences, University of Mississippi Medical Cen-
ter, Jackson, MS (Sherer, Nick); Department of Physical Medicine and Rehabilitation,
Baylor College of Medicine, Houston, TX (Sander, High); Brain Injury Research
Center, The Institute for Rehabilitation and Research, Houston, TX (Sander, High);
Department of Psychiatry and Psychology, Mayo Medical Center/Medical School,
Rochester, MN (Malec); Kessler Medical Rehabilitation Research and Education
Corp, West Orange, NJ (Rosenthal); and Department of Physical Medicine and
Rehabilitation, UMDNJ–The New Jersey Medical School, Newark, NJ (Rosenthal).
Accepted in revised form February 26, 2001.
Supported by the National Institute on Disability and Rehabilitation Research.
No commercial party having a direct financial interest in the results of the research
supporting this article has or will confer a benefit upon the author(s) or upon any
organization with which the author(s) is/are associated.
Reprint requests to Mark Sherer, PhD, ABPP/Cn, Methodist Rehabilitation Center,
1350 E Woodrow Wilson, Jackson, MS 39216, e-mail: marks@mmrcrehab.org.
0003-9993/02/8302-6540$35.00/0
doi:10.1053/apmr.2002.28802
183
Arch Phys Med Rehabil Vol 83, February 2002