Cognitive Rehabilitation Therapy for Traumatic Brain Injury:

Transcription

Cognitive Rehabilitation Therapy for Traumatic Brain Injury:
Cognitive Rehabilitation Therapy for Traumatic Brain Injury:
What We Know and Don’t Know about Its Efficacy
EDITORIAL NOTE 10/11/11:
IOM’s New Report on Brain Injury Treatments Draws Conclusions Similar to ECRI
Institute’s Earlier Findings
On October 11, 2011, the Institute of Medicine (IOM) released its report on cognitive rehabilitation therapy
(CRT) for traumatic brain injury (Cognitive Rehabilitation Therapy for Traumatic Brain Injury: Evaluating
the Evidence). The report, commissioned by the U.S. Department of Defense (DOD), generally concurs with
the findings of ECRI Institute’s systematic review, which was also commissioned by DOD and published
October 31, 2009 (Cognitive Rehabilitation for the Treatment of Traumatic Brain Injury). Both reports found
some evidence that CRT is effective for improving some of the deficits associated with traumatic brain injury,
but that overall the evidence was insufficient to determine the full therapeutic value of cognitive rehabilitation
therapy.
Both reports emphasized that limited evidence does not mean that cognitive rehabilitation therapy does
not work and more research is necessary to definitively determine the overall efficacy and effectiveness
of cognitive rehabilitation therapy. Future research should also consider under which circumstances
cognitive rehabilitation therapy would be most beneficial to individual patients.
The two reports differed in the criteria used to select studies for review and the number of studies included in
the reviews. However, both reports identified similar methodological limitations in the studies they included
as the source of the insufficiency of the evidence. Among the limitations were variation in the outcomes
assessed in the studies, differences in the types of cognitive rehabilitation therapy methods/strategies
employed across studies, and small sample sizes of the studies.
Survivors of traumatic brain injury in the military and in civilian life deserve the best care that our health
systems can provide as they contend with their physical and cognitive impairments. As researchers fill in the
gaps in scientific knowledge, patients with traumatic brain injury will benefit.
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Following is an overview of ECRI Institute’s 2009 systematic review of the scientifically based medical
literature published on cognitive rehabilitation therapy for treating traumatic brain injury resulting from
external trauma. ECRI Institute (www.ecri.org) is an independent nonprofit organization that researches
the best approaches to improving patient care and is designated an Evidence-based Practice Center by the
U.S. Agency for Healthcare Research and Quality.
 What Did ECRI Institute Conclude?
In our report, we carried out several meta-analyses using data from 18 randomized controlled trials. Based on data
from these studies, we were able to conclude the following:

Adults with moderate to severe traumatic brain injury who receive social skills training perform significantly
better on measures of social communication than patients who receive no treatment.

Adults with traumatic brain injury who receive comprehensive cognitive rehabilitation therapy report
significant improvement on measures of quality of life compared to patients who receive a less intense form
of therapy.
The strength of the evidence supporting our conclusions was low due to the small number of studies that addressed
the outcomes of interest. Further, the evidence was too weak to draw any definitive conclusions about the
effectiveness of cognitive rehabilitation therapy for treating deficits related to the following cognitive areas: attention,
memory, visuospatial skills, and executive function. The following factors contributed to the weakness of the
evidence: differences in the outcomes assessed in the studies, differences in the types of cognitive rehabilitation
therapy methods/strategies employed across studies, differences in the control conditions, and/or insufficient number
of studies addressing an outcome.
 What Causes Traumatic Brain Injury?
Traumatic brain injury can result from external physical shocks, such as those potentially experienced in automobile
accidents, explosions, or blows to the head. The severity of such an injury may range from mild (i.e., a brief change in
mental state or consciousness) to severe (i.e., an extended period of unconsciousness or amnesia after the injury) and
can cause temporary or permanent impairments of cognitive, physical, and psychosocial functions.
 What Is Cognitive Rehabilitation Therapy?
Cognitive rehabilitation therapy is one form of therapy available for patients with traumatic brain injury, who as a
result of their injury suffer from cognitive deficits such as memory loss or attention problems. Individuals with
traumatic brain injury often need a variety of therapeutic interventions including physical therapy, occupational
therapy, speech and language therapy, psychotherapy, vocational therapy and pharmacologic therapy.
The delivery of cognitive rehabilitation therapy varies depending on the particular deficits resulting from traumatic
brain injury, on the provider, and on the treatment setting. There continues to be much debate among providers about
when to initiate treatment, what specific treatment strategies to employ, what intensity or dose of treatment to provide,
and for how long to provide treatment. However, approaches to cognitive rehabilitation therapy are generally
separated into two broad categories: restorative and compensatory. The restorative approach focuses on reinforcing,
strengthening, or restoring functions that remain partially intact after the injury, whereas the compensatory approach
focuses on teaching patients to use strategies to cope with the impairment.
Restorative interventions include a number of computer or pen and paper exercises designed to isolate specific
components of impaired cognition (e.g., selective attention, memory for new information).
Compensatory methods typically focus on activities of daily living, such as remembering the sequence of tasks
required to get ready for work in the morning. Compensatory techniques might include use of electronic memory
devices, alarms, calendars, or reminders posted around the house.
Cognitive rehabilitation therapy may be delivered in an inpatient or outpatient setting, depending on the severity of
injury. It is sometimes provided within the context of a comprehensive treatment program designed not only to
address the person’s cognitive deficits, but also to help with other issues such as emotional difficulties, problematic
interpersonal behaviors, and physical impairments.
 ECRI Institute’s Systematic Review of the Literature
In 2009, ECRI Institute completed a systematic review or assessment of the scientifically based medical literature
published on cognitive rehabilitation therapy for treating traumatic brain injury resulting from external trauma. That
is, we examined data from multiple published studies that we believe have the most scientific validity, using metaanalysis, a technique that permits researchers to combine data from these separate studies, and narrative descriptions
of studies when meta-analysis was not possible.
Our report addressed several questions about the efficacy of cognitive rehabilitation therapy, including questions
about its efficacy for treating specific cognitive deficits (e.g., memory loss, attention difficulties, and communication
problems) and for improving the overall functioning and quality of life of individuals who experience a traumatic
brain injury. We also considered questions about the level of intensity at which cognitive rehabilitation therapy is
delivered. For example, we looked at the evidence in which cognitive rehabilitation therapy was designed to address
multiple cognitive deficits sequentially or simultaneously and whether it was used within a comprehensive versus a
less intensive treatment setting.
 Who Asked Us to Carry Out This Study?
The report was originally commissioned by TRICARE, the health insurance program for military personnel, military
retirees, and their dependents. The numbers of military personnel and veterans in whom traumatic brain injury has
been diagnosed has increased because the wars in Iraq and Afghanistan have exposed active-duty personnel to blast
injuries, including those from improvised explosive devices. Our report, however, informs a broader audience of
decision makers. This includes researchers seeking to fill gaps in the scientific understanding of how well the therapy
works; providers trying to make decisions about whether to provide cognitive rehabilitation therapy in lieu of, or as an
adjunct to, other treatments for traumatic brain injury; and insurers wanting to use scientific evidence to aid in their
deliberations about whether to provide coverage for this therapy or to decide which providers, settings, or forms of
cognitive rehabilitation therapy provide the greatest benefit.
ECRI Institute reports never make coverage or payment recommendations to insurers. The Institute is focused on
analyses of the scientific literature. When this literature also reports on costs, we present this information without
making a judgment on whether the costs are too high.
Although ECRI Institute provided this report to TRICARE, we reported the same results to hospitals and our other
constituencies.
 What Method Did ECRI Institute Use to Assess the Existing Studies and Why?
The goal of ECRI Institute’s review was to assess the evidence that most appropriately addressed questions about the
efficacy of cognitive rehabilitation therapy for treating traumatic brain injury. The methodology of this particular
report was restricted to an evaluation of randomized controlled trials, experimental study designs in which individuals
are randomly assigned (on the basis of chance) to a treatment group or a control group (e.g., placebo, standard
therapy, or other treatment). Randomized controlled trials are the most accepted scientific method of determining the
benefit of a therapeutic procedure and represent the best available evidence for this intervention and condition. Other
types of study designs, such as clinical studies with nonrandom assignment or those without a control group (e.g.,
single-group before and after studies) can provide preliminary evidence as to whether a therapy holds some promise.
For some conditions that are unlikely to spontaneously improve or to fluctuate in severity, these non-randomized
controlled trials designs may provide sufficient evidence for benefit.
Non-randomized or uncontrolled trials were not included in ECRI Institute’s assessment of the efficacy of cognitive
rehabilitation therapy because of the potential for bias in this situation. For instance, one study design commonly used
in the cognitive rehabilitation therapy literature is the single-group before and after (pre-post) design. In studies that
employ this design, a group of individuals with traumatic brain injury are tested on an outcome of interest (e.g., social
communication skills) before receiving the intervention and then are retested on that outcome after receiving the
intervention. The pre-post assessment of the outcome is intended to measure any change or improvement that results
from receiving the intervention. However, a number of alternative factors may also explain changes observed in this
type of study. These factors include spontaneous recovery (e.g., improvements in cognitive functioning that may
occur without therapy that specifically targets cognitive problems); testing effects (i.e., practice effects of taking a pretest and then taking it again as the post-test); and placebo effects (i.e., improvements that may result from
individualized attention received by patients in a study, regardless of the specific intervention). Thus, randomized
controlled trials were considered the most appropriate source of evidence for the questions posed in this report
because they allow researchers, clinicians, and the public, including patients and their lay caregivers, to distinguish
between the effectiveness of cognitive rehabilitation therapy and other factors that might lead to false conclusions
about whether the therapy is actually working.
An assessment of the scientific literature on cognitive rehabilitation therapy is further complicated by a number of
controversies within the field. These controversies are apparent in the literature on cognitive rehabilitation therapy, as
studies vary considerably in terms of the strategies employed and the duration of treatment. For instance, the types of
therapeutic interventions used in the studies included in our report that focused on improving memory deficits ranged
from spaced retrieval training (a method of learning and retaining information by recalling information over
increasingly longer periods of time) to the use of various internal memory aids such as mnemonic strategies (use of
word or image association) and external memory aids such as memory notebooks or diaries. The duration of treatment
in these studies ranged from 18 to 132 hours.
 Perspective on the Study
ECRI Institute believes it is important for readers of any technology assessment to appreciate that the assessment must
rely on research done to date that meets the criteria for the particular review. When the research does not allow the
assessor to draw a conclusion about effectiveness, it does not mean that a therapy, like cognitive rehabilitation, does
not work. As researchers fill in the gaps in scientific knowledge, patients with traumatic brain injury will benefit.
Scientifically based evaluation studies are, in our view, a vital element in understanding what treatments are effective
and are in the best interest of patients and professionals.
Please direct any questions on this issue to [email protected].