Evidence Report/Technology Assessment: Number 2
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Under its Evidence-based Practice Program, the Agency for Health Care Policy and Research (AHCPR) is developing scientific information for other agencies and organizations on which to base clinical guidelines, performance measures, and other quality improvement tools. Contractor institutions review all relevant scientific literature on assigned clinical care topics and produce evidence reports and technology assessments, conduct research on methodologies and the effectiveness of their implementation, and participate in technical assistance activities.
Overview / Impact of TBI / Key Questions / Reporting the Evidence / Methodology / Findings / Future Research / Availability of Full Report
Advances in medical technology and improvements in regional trauma services have increased
the number of survivors of traumatic brain injury (TBI), producing the social consequences and
medical challenges of a growing pool of people with disabilities. Wider awareness of the scope
of the problem and its consequences for society has led to rapid growth in the rehabilitation
industry. Because of this growth and particularly because clinical rehabilitation strategies vary
widely, many groups are interested in the effectiveness of rehabilitation for TBI.
To address this need to identify and assess evidence on TBI rehabilitation, the Agency for Health
Care Policy and Research (AHCPR) awarded a contract to Oregon Health Sciences University for a review
of published reports and compilation of an evidence report. This summary highlights information
presented in the full report.
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Impact of Traumatic Brain Injury
Injury is the leading cause of mortality among Americans under 45 years of age; TBI is
responsible for the majority of these deaths. An estimated 56,000 lives are lost in the United
States each year to TBI. Motor vehicle accidents, followed by gunshot injuries and falls, are the
leading causes of injuries resulting in death from TBI. Males are 3.4 times as likely as females to
die of TBI. About 50 percent of people who sustain TBI are intoxicated at the time of injury.
In a recent analysis based on hospital discharge data and vital statistics, the annual incidence of
TBI in the United States was estimated to be 102.8 per 100,000. In males, the incidence peaks
between the ages of 15 and 24 (248.3 per 100,000) and again above 75 years of age (243.4 per
100,000). The incidence in females peaks in the same age groups, but the absolute rates are lower
(101.6 and 154.9, respectively). These rates underestimate the true incidence of head trauma
because patients with milder symptoms at the time of injury are usually not hospitalized.
About three-quarters of traumatic brain injuries that require hospitalization are nonfatal. Each
year, about 80,000 survivors of TBI will incur some disability or require increased medical care.
Direct medical costs for TBI treatment have been estimated at $48.3 billion per year, including
the costs of hospitalization for acute care and various rehabilitation services.
In the years 1988 to
1992, reports of average length of stay (LOS) for the initial admission for inpatient rehabilitation
range from 40 to 165 days. In one multicenter study (the Model Systems study), the average
rehabilitation LOS was 61 days, and the average charge was $64,648 exclusive of physician fees.
Total charges averaged $154,256. In more recent studies performed in the early 1990s,
rehabilitation LOS and charges were lower, ranging from 19 days and $24,000 for patients with
milder injuries to 27 days and $38,000 for those with severe injuries. In the Medicare population
in 1994, mean charges for patients admitted for brain injury (excluding stroke) were $42,056.
To focus attention on important questions, the life of an adult survivor of TBI was characterized
by the developers of the report in terms of five phases. The first phase is pre-injury. Medical
treatment is divided into two phases: the acute (or immediate) treatment phase and the intensive
treatment phase, lasting days to weeks. The rehabilitation phase may last months to years. The
survivor phase implies the remaining life of the person with TBI and involves continual
development and adjustment. This division into phases clarifies the three challenges to assessing
the efficacy of rehabilitation discussed above. For each phase, patient populations, interventions,
and outcome measures were identified, and the literature was reviewed to answer key questions
identified by technical experts.
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Key Questions About Traumatic Brain Injury
The following three questions about the status of brain injury research underlie uncertainty about
the effectiveness of rehabilitation services.
- How should fundamental concepts such as recovery, functional status, and disability be
defined? Because brain function is highly complex, TBI has an extremely wide range of potential
outcomes, including cognitive deficits, motor disabilities, emotional and social dysfunction,
personality changes, and changes in appearance. As a result, therapeutic aims and perspectives
vary widely among studies, as do definitions of outcomes, making valid comparisons across
- How should the type and severity of the injury itself be measured? Variations in methods
to assess the severity of injury in patients entering rehabilitation make it difficult to estimate the
effectiveness of different rehabilitation methods.
- Which therapies are effective, and what is the best way to match patients with treatment
approaches likely to be effective for them?
Today, a person's path to rehabilitation after sustaining brain injury may be determined by the
mechanism of injury, the resources of the community, the person's employment or financial
status, the consent of the family, and/or the accuracy of the emergency department diagnosis.
While a few metropolitan areas have organized referral systems that connect patients with
resources and rehabilitation programs, systematic methods for evaluating the needs of people
who have sustained brain injury and referring them to appropriate programs are unusual. Without
knowing the efficacy of rehabilitation methods in their specific applications, systematic referral that produces the desired result is not possible.
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Reporting the Evidence
Two panels of experts worked with the research team to identify key questions in the
rehabilitation and survivor phases for adults with TBI. The first panel was composed of two
physiatrists, a survivor of TBI, the wife of a survivor of TBI, a State vocational rehabilitation
counselor, a neuropsychologist, a psychologist, a clinical coordinator of an outpatient TBI
rehabilitation program, and a rehabilitation clinical nurse specialist, all from the Portland, OR,
area. The second panel was composed of nationally recognized experts in rehabilitation.
The panels formulated five questions pertaining to the phases of recovery described above. These
questions addressed the effectiveness of (1) early rehabilitation in the acute care setting (timing),
(2) intensity of rehabilitation, (3) cognitive rehabilitation, (4) supported employment, and (5)
care coordination (case management). For each of these questions, members of the research team
worked with panelists to write a brief rationale for the question, define key terms, and specify the
relevant patient populations, interventions, and outcome measures to be examined in the
literature review. The questions were:
- Should interdisciplinary rehabilitation begin during the acute hospitalization for traumatic
- Does the intensity of inpatient interdisciplinary rehabilitation affect long-term outcomes?
- Does the application of cognitive rehabilitation enhance outcomes for people who sustain
- Does the application of supported employment enhance outcomes for people with TBI?
- Does the provision of long-term care coordination enhance the general functional status
of people with TBI?
Select for Findings.
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A MEDLINE® search (1976 to 1997), supplemented by searches of HealthSTAR (1995 to 1997),
CINAHL (1982 to 1997), and PsycINFO (1984 to 1997), produced a total of 3,098 references to
be considered for inclusion; of these, 569 applied to questions 1 and 2, 600 applied to question 3,
392 applied to question 4, and 975 applied to question 5.
Abstracts of each article retrieved by these searches were reviewed independently by two
members of the research team, who applied predefined, broad eligibility criteria. When the two
reviewers disagreed, a third reviewer read the abstract and cast the deciding vote on whether it
should be included. In the event a reference did not have an abstract, and the title for the
reference was not sufficient for determination of status, the article was retrieved and reviewed to
determine its eligibility. The two reviewers examined each abstract and indicated whether it met
the inclusion criteria and, if not, the reason for exclusion. If the abstract was eligible, or if it did
not contain sufficient information to determine eligibility, the full text of the article was retrieved
for review in the next phase of the selection process.
Eighty-seven articles pertaining to questions 1 and 2, 114 articles for question 3, 93 articles for
question 4, and 69 articles for question 5 passed the eligibility screen. Sixty-seven additional
articles were recommended for inclusion by experts or by review of reference lists of review
articles. In all, 363 articles were retrieved for review and abstraction.
Additional criteria for inclusion were defined separately for each of the five questions. The
criteria varied because the necessary types of studies varied from question to question. Articles
that applied to more than one question were maintained as duplicates (or triplicates, etc.) in each
question-specific file, so they could be considered for inclusion based on their relevance to each
An instrument was designed to record data abstracted from each eligible article. The instrument
includes items for patient characteristics, interventions, cointerventions, outcomes, study
methods, relevance to the specific research questions, and results of the study. The instrument
has two components: the first four pages of the instrument apply to all articles specified for
inclusion in the study; the remaining pages are individual instruments that apply to one of the
five questions. To abstract an article, a reader used the initial abstraction instrument plus one or
more of the five question instruments.
The first few questions of the initial abstraction instrument allowed the reviewer to determine if
the article actually met the eligibility criteria for inclusion in the report. If an article was
determined to be ineligible, it was passed to a second reader for confirmation. The remaining
articles were subjected to the full abstraction protocol.
Specification of Level of Evidence
A three-level system was used to rate individual studies. Well-designed randomized controlled
trials (RCTs) were rated as Class I. Studies rated as Class II were RCTs with design flaws;
well-done, prospective, quasiexperimental or longitudinal studies; and case-control studies. Case
reports, uncontrolled case series, and expert or consensus opinion were generally rated Class III.
A well-done, prospective, multicenter or population-based case series can provide valuable
information that, in some ways, is more reliable than data from a randomized trial done in a
highly selected sample of patients. However, when used to make inferences about effectiveness,
an uncontrolled case series is generally classified as Class III, indicating the lowest level of
A "gray zone" exists between Class II and definite Class III articles. Much of the research in
rehabilitation uses quasi-experimental designs. In these observational study designs, control
subjects are sometimes identified from a separate patient population. For instance, one group of
researchers compared patients undergoing inpatient rehabilitation to a sample of people with TBI
who had been treated in a region of the country where formal inpatient TBI rehabilitation was not
available. This was an entirely separate patient group, and all the data except outcome measures
came from an independent database.
The main difficulty with the quasiexperimental design is lack of control over the constitution of
the compared groups. Because there is no randomization and generally no control over the details
of the selection process through which the patients received their separate therapies, the groups
are likely to differ in the frequency of characteristics that are associated with the outcomes of
interest. Even when significant efforts are made to match the experimental and the quasi-control
groups, it is likely that significant differences between the groups will remain.
Much of the literature relevant to the five questions addressed in this effort falls into the "gray
zone" between Class II and Class III. For this reason, critical appraisal of key studies played a
particularly important role in this review. A number of characteristics of these studies were
considered relevant to all rehabilitation questions and were recorded in the data abstraction form.
Evaluation of the following factors played a major role in critically appraising these articles:
- Prospective collection of data.
- Complete description of parent study population.
- Large study population driven by hypothesis, power, type I error threshold).
- Study setting—a single center, many centers, or population based.
- Description of reasons for referral to service being studied.
- Description of methods sufficiently complete to permit study replication.
- Complete description of rehabilitation technique in question (independent variable).
- Complete description of differences between "control" and "experimental" groups.
- Conditions determining whether patients did or did not receive the rehabilitation
technique in question.
- Information about potential confounders, including types and severity of injury, age, and
others (including in some cases, economic status, educational level, lack of family support).
- Measurement of confounding variables using instruments validated as accurate, sensitive,
- Payer group.
- Choice of outcome variables that are meaningful to patients and caregivers.
- Use of functional status and other health outcomes rather than surrogate (intermediate)
- Measurement of outcome variables using instruments validated as accurate, sensitive, and
- Timing of outcome measurements.
- Assessment of patient characteristics and outcomes by blinded observer.
- Use of multivariate statistical analysis: Were interactions sought and controlled for? Were
risk estimates calibrated? Were all relevant confounders included as candidate variables?
The criteria used to classify articles and the features to be considered in critically appraising them
were discussed at the subcommittee, committee, national expert panel, and Aspen
Neurobehavioral Conference levels with the goal of maintaining consensus at least on the relative
stratification of individual articles.
Construction of Evidence Tables
Evidence tables were constructed to summarize the best evidence about effectiveness pertaining
to each question. No randomized trials and only a few quasiexperimental studies were available
for questions 1 and 2. There were a large number of relevant observational studies of important
relationships (for example, the relation of patient characteristics to outcome); studies that
concerned individual causal links or relationships in evidence tables were not summarized. For
question 3, addressing cognitive rehabilitation, 15 randomized controlled trials and comparative
studies that met specified inclusion criteria were placed into evidence tables. All comparative
studies located for the last two questions, which addressed supported employment and care
coordination, were included in evidence tables.
Critical Appraisal of Key Articles
For each of the five questions, subcommittees were formed consisting of one or two members of
the research team and one or two members of the local technical panel. Each subcommittee was
chaired by a member of the research team. Key articles relevant to the assigned question were
reviewed in depth by all members of the subcommittees. These reviews were discussed among
the various members of the subcommittees, and the results were summarized by the chair. This
was an effort to ensure that the summary statements on the research questions reflected the
expertise and experience of a variety of technical experts with relevant skills and training. These
interpretive efforts addressed the methods and results of individual studies, their rating, and their
All of the critical articles for the five questions were individually read by the principal
investigator. Summaries were presented and discussed with national experts at the Aspen
Neurobehavioral Conference in April 1998.
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One small, retrospective, observational study from a single rehabilitation facility supports an
association between the acute institution of formalized, multidisciplinary, physiatrist-driven TBI
rehabilitation and decreased length of stay (acute hospital and acute rehabilitation) and some
measures of short-term physiologic (noncognitive) patient outcomes. The level of evidence is
Class III. This study concerned adult patients with severe brain injury (Glasgow Coma Scale
3-8); there is no evidence from comparative studies for or against early rehabilitation in patients
with mild and moderate injury.
When measured as the hours of application of individual or grouped therapies, there is no
indication that the intensity of acute, inpatient TBI rehabilitation is related to outcome. Because
of methodological weaknesses, however, previous studies are likely to have missed a significant
relationship if one exists (a type 2 error). These studies contained insufficient information about
severity of injury and baseline function to ensure the comparability of compared groups. Also,
these studies did not consider the quality of individual treatments, their lack of autonomy in the
cognitive realm, and the delivery milieu. One or more of these factors may affect the outcome of
care more than the time spent in each modality. Therefore, future research into efficacy of acute
inpatient TBI rehabilitation must more adequately measure such factors and include the factors in
their predictive models. Future studies also must employ a wider spectrum of outcome measures,
including measurement of outcomes across longer periods of time after discharge.
From a clinical aspect, the evidence does not support equating different TBI rehabilitation
delivery systems based on equivalent times of patient exposure to various therapeutic modalities.
For example, this analysis would not support predicting that patient benefit would be equal if an
equal time spectrum of rehabilitation therapies were delivered at a rehabilitation center as
compared with a skilled nursing facility. More detailed analysis of factors involved in predicting
response to rehabilitation modalities must be considered in approaching such questions.
Additionally, mandating a minimum number of hours of applied therapy for all TBI patients is
not supported by the present state of scientific knowledge. How much of which intervention(s)
optimizes recovery in a given type of patient has been inadequately studied. It is certainly
reasonable to avoid situations in which patients do not receive potentially beneficial treatment.
Based on the above studies, however, defining a minimal rehabilitation program in terms of time
of applied therapy is not likely to optimize either the therapists' time or patients' recovery. It is
probable that specific basic programs will have to be related to individual patient groups.
Developing such algorithms requires further research.
Many patients who suffer TBI do not enter acute inpatient rehabilitation. Only one study of the
effectiveness of inpatient rehabilitation included a comparison group of patients who did not
undergo inpatient rehabilitation. Future studies should compare acute, inpatient rehabilitation to
commonly used alternatives to inpatient rehabilitation, such as care in a well-staffed skilled
nursing facility or in less intense variations of acute rehabilitation. Very little is known about the
outcomes of TBI in these settings.
There is evidence from two small studies (Class I and Class III) that a personally adapted
electronic device, a notebook, and an alarm wristwatch reduce everyday memory failures for
people with TBI. There is evidence from one study (Class II[a]) that compensatory cognitive
rehabilitation (CCR) reduces anxiety and improves self-concept and relationships for people with
TBI. Evidence from two studies (Class I and Class II[b]) supports the use of computer-aided
cognitive rehabilitation (CACR) to improve immediate recall on neuropsychological testing, but
the clinical importance of this finding has not been validated.
Class II evidence indicates that supported employment can improve the vocational outcomes of
TBI survivors. Nearly all information about supported employment comes from two bodies of
work, each of which used different experimental designs and different models of supported
employment. The findings have not been replicated in other settings or by other centers, so the
generalizability of these programs remains untested.
There have been very few studies on the effectiveness of case management, and the results of
these studies are mixed. The only outcome for which there were results in the same direction
from two or more studies pertained to changes in vocational status. This was associated with the
single case-manager and insurance approach, as well as with the combined nurse and vocational
case-manager model. There were conflicting results about the effects of case management on
disability or functional status, living status, family impact, and other aspects, and some findings
were mentioned in only one study. The clinical trial resulted in no functional status changes
among case-managed subjects, despite an extended period of rehabilitation. However, when two
forms of case management were compared, both the single and multiple case-manager/insurance
approaches showed significant functional improvements.
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The evidence report identifies the following areas for future research.
- Randomized trials of the timing and intensity of early and acute rehabilitation would be
useful. Because the patient characteristics that affect outcomes also affect the type and level of
rehabilitation services delivered, it may be unlikely that any observational study can provide
definitive evidence about effectiveness. Moreover, assigning patients to different levels of
intensity or to early versus conventional initiation of rehabilitation in a prospective trial may be
ethically acceptable, since these different levels represent a range of current practice rather than a
deviation from it.
- Population-based studies of all patients with TBI, including those who do not enter
inpatient rehabilitation facilities, are imperative. Important questions about the effectiveness of
rehabilitation and its component disciplines require the development of regional or national
registries, with standardized data collection and identification and followup of all patients with
- Research designs for future studies should incorporate health outcomes of importance to
people with TBI and their families. Commonly used measures should be more strongly linked to
health outcomes. Future studies should address the effect of spontaneous recovery, systematize
criteria for entering cognitive rehabilitation, and differentiate between the effects of general
stimulation and specific techniques.
- The greatest overall need for the evaluation of supported employment programs is a series
of trials with adequate controls and unbiased allocation of clients to the conditions compared.
- Future research should focus on improving the outcome measures used to examine the
results of case management in TBI rehabilitation. In addition to outcomes of changed patient
functionality, there should be outcomes of changed family functionality. Since much of case
management communication is directed toward helping family members learn what to expect and
where to obtain services, relevant outcomes would include family use of community and
rehabilitation services and indicators of family assertiveness about care expectations. While case
management may exert only an indirect effect on a patient's functional outcomes such as level of
disability, vocational status, and living status, it is possible that case management can directly
affect family knowledge of TBI rehabilitation needs and services, level of psychosocial anxiety,
and family competency in coping with TBI.
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Availability of the Full Report
The full evidence report from which this summary was taken was prepared for AHCPR by the Oregon Health Sciences University, Portland, OR, under
contract No. 290-97-0018. The Evidence Report is archived online at the National Library of Medicine Bookshelf. Print copies are no longer available.
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AHCPR Publication No. 99-E005
Current as of October 1999