Preface: Ecological Validity in Traumatic Brain Injury
When confronted with defining the needs of a survivor of traumatic brain injury (TBI), health care professionals often struggle with reconciling objective norm-based data with clinical observations of a particular individual's cognitive strengths and weaknesses in the context of their typical environment. Many times the assessment data alone does not accurately reflect the survivor's actual capabilities, making prediction of future needs and abilities difficult. This dilemma also continues into the realm of rehabilitation, in that objective measures and models of treatment are difficult to validate. This issue of validity of assessment and treatment has become all the more pertinent in this age of managed health care, as clinicians seek methods of quantifying an individual's functional abilities (and growth) in a data-based yet meaningful manner.
The concept of “ecological validity” refers to the extent by which clinical assessments and treatment are associated with a survivor's functional abilities in their day-to-day environments. The push to establish ecologically valid approaches for individuals following a TBI has been felt in all aspects of rehabilitation. This issue of the Journal of Head Trauma Rehabilitation (JHTR 15:4) addresses the limitations involved in making valid generalizations from standardized assessment techniques (administered in highly structured and protected clinic environments) to more naturalistic environments, the potential use of situational assessments in overcoming some of the generalization problems, and treatment models that have as their basis a focus on impairment environmental interactions. Our hope is that the information presented here will allow both a theoretical understanding of the challenges related to ecological validity and practical ways of overcoming those challenges.
After children experience a TBI, the resulting deficits frequently impact future academic, interpersonal, and ultimately vocational abilities. Although there has been a recent increase in research regarding the ecological validity of neuropsychological assessment of adults, there have been few studies performed that clarify the relationship between neuropsychological assessment and functional ability in children. Silver describes factors that impede the ability to obtain ecologically valid measurements, reviews the current pediatric neuropsychological literature in the area of ecological validity, and provides suggestions for future areas of research.
Adult survivors of TBI frequently experience disturbances of executive functioning and behavior that may impact most aspects of day to day functioning and vocational ability. The ability to objectively assess executive functioning in an ecologically valid manner has remained elusive to clinicians. McCue and Pramuka review the recent developments in the literature describing creative, yet scientific methods of assessing executive functioning, based upon current theoretical understandings of this intricate aspect of cognition. Yody and colleagues address the issue of maladaptive behaviors following a TBI, providing a model for treatment that combines functional behavioral assessment and a community-based neurobehavioral rehabilitation strategy. This approach is designed to promote appropriate behaviors across a variety of real-life settings, addressing all aspects of daily functioning in an ecologically valid manner. One particular emphasis of their model is the need for clinicians to be aware of their role in a survivor's maladaptive behaviors, describing the importance of in-depth training of all staff that interacts with the individual during the rehabilitation process.
Standard neuropsychological measures can be lacking when attempting to predict a survivor of TBI's vocational abilities. An alternate method of assessment which McCue and Pramuka mention in their review is situational assessment. LeBlanc and associates further explore the meaningfulness of this approach in a research study which compares the results of a formal neuropsychological assessment battery and the findings of a three to five day vocational situational assessment in predicting employability for 127 survivors of moderate to severe TBI's, in predicting employability. Results from this research support the need for combining standard assessment techniques with in-depth observational data for prediction of “real-world” abilities in this population of individuals.
When a survivor of TBI participates in rehabilitation directed towards a return to employment, Kowalske and colleagues point out the need to define the environmental factors that influence actual vocational performance, in addition to specific cognitive abilities. In their review of three diverse case studies of TBI survivors, they describe an environmentally based treatment model that promotes a successful return to employment. Hayden and associates provide a more thorough description of the aforementioned treatment model and provide outcome data for sixty-one survivors of TBI who successfully completed this treatment program. Issues discussed include overall efficacy, the impact of possible secondary gain issues, and the challenges of using measures associated with handicap.
It is our desire that this review of ecological validity in reference to assessment and rehabilitation will stimulate an interest in developing creative approaches to assessment, treatment, and research that result in a better understanding of the complex interactions that control the level of independence each individual who survives brain injury achieves. As indicated by the founders of JHTR, it is important that health care professionals continue to, “…improve our knowledge base, our clinical expertise, and ultimately the lives of those we treat and of their families.” 1(pvii) A professional demand for ecologically valid assessment and treatment of survivors of TBI will ensure that our areas of expertise in health care continue to provide meaningful intervention to those we are privileged to treat.