OUTCOME PREDICTION is one of the most important

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1 950 SPECIAL SECTION: ORIGINAL ARTICLE The Predictive Validity of a Brief Inpatient Neuropsychologic Battery for Persons With Traumatic Brain Injury Robin A. Hanks, PhD, Scott R. Millis, PhD, Joseph H. Ricker, PhD, Joseph T. Giacino, PhD, Risa Nakese-Richardson, PhD, Alan B. Frol, PhD, Tom A. Novack, PhD, Kathleen Kalmar, PhD, Mark Sherer, PhD, Wayne A. Gordon, PhD ABSTRACT. Hanks RA, Millis SR, Ricker JH, Giacino JT, Nakese-Richardson R, Frol AB, Novack TA, Kalmar K, Sherer M, Gordon WA. The predictive validity of a brief inpatient neuropsychologic battery for persons with traumatic brain injury. Arch Phys Med Rehabil 2008;89: Objective: To examine the predictive validity of a brief neuropsychologic test battery consisting of the Galveston Orientation and Amnesia Test, the California Verbal Learning Test II, Trail-Making Test (TMT), Symbol Digit Modalities Test, grooved pegboard, phonemic and categorical word generation tasks, the Wechsler Test of Adult Reading (WTAR), and the Wisconsin Card Sorting Test 64 relative to functional outcome at 1 year in persons with traumatic brain injury. Design: Inception cohort study. Follow-up period of 12 months. Setting: Seven Traumatic Brain Injury Model System centers. Neuropsychologic testing was conducted during the acute inpatient rehabilitation stay and functional outcome measures were obtained at 1-year outpatient follow-up. Participants: Adults (N 174) who met criteria for admission to inpatient brain injury rehabilitation. Interventions: Not applicable. Main Outcome Measures: FIM instrument, Disability Rating Scale, Supervision Rating Scale, Satisfaction With Life Scale (SWLS), and Glasgow Outcome Scale Extended. Results: Multiple regression analyses revealed that performance on the neuropsychologic test battery was predictive of outcome at 1 year postinjury for all outcome measures, except FIM motor scores and the SWLS. Cognitive performance using this battery was found to predict 1-year outcomes above and beyond functional variables and injury collected during inpatient rehabilitation, thereby indicating incremental validity for this test battery. Individual tests that were From Department of Physical Medicine and Rehabilitation, Wayne State University School of Medicine, Detroit, MI (Hanks, Millis); Rehabilitation Institute of Michigan, Detroit, MI (Hanks, Millis); Department of Physical Medicine and Rehabilitation, University of Pittsburgh, Pittsburgh, PA (Ricker); JFK Johnson Rehabilitation Institute and New Jersey Neuroscience Institute, JFK Medical Center, Edison, NJ (Giacino, Kalmar); Methodist Rehabilitation Center, Jackson, MS (Nakese-Richardson); University of Mississippi Medical Center, Jackson, MS (Nakese-Richardson); Department of Physical Medicine and Rehabilitation, Baylor Institute for Rehabilitation, Dallas, TX (Frol); Spain Rehabilitation Center, Birmingham, AL (Novack); Memorial Hermann/TIRR, Houston, TX (Sherer); and Department of Rehabilitation Medicine, Mount Sinai School of Medicine, New York, NY (Gordon). Supported by the National Institute on Disability and Rehabilitation Research (grant nos. H133A020501, H133A020502, H133A020509, H133A020514, H133A020515, H133A020518, H133A020526). 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 authors or upon any organization with which the authors are associated. Reprint requests to Robin A. Hanks, PhD, ABCN, Rehabilitation Institute of Michigan, 261 Mack Blvd, Detroit, MI 48201, rhanks@med.wayne.edu /08/ $34.00/0 doi: /j.apmr found to be significant predictors of 1-year outcomes included the WTAR and TMT part B. Conclusions: These findings support the clinical utility and ecological validity of this battery with respect to level of disability, functional independence, and supervision required. Key Words: Brain injuries; Neuropsychological tests; Outcomes assessment (health care); Psychometrics; Rehabilitation by the American Congress of Rehabilitation Medicine and the American Academy of Physical Medicine and Rehabilitation OUTCOME PREDICTION is one of the most important and challenging tasks faced by clinicians involved in acute inpatient traumatic brain injury (TBI) rehabilitation. Establishing an accurate prognosis is essential for planning current rehabilitation goals, identifying appropriate postacute care needs, educating caretakers about long-term medical and psychosocial issues, and rationing financial resources. Neuropsychologic assessment is commonly conducted in association with other neurodiagnostic procedures (eg, neuroimaging studies) and has been shown to predict functional outcome at various stages of recovery. 1 A number of empirical studies have examined the role of neuropsychologic test performance in the prediction of outcome after TBI. Hart at al 2 assessed 452 adults enrolled in the Traumatic Brain Injury Model Systems (TBIMS) at 1 year postinjury on a battery of neuropsychologic tests including the Galveston Orientation and Amnesia Test (), token test, Wechsler Memory Scale Revised (WMS-R) (logical memory subtest), digit span, Trail-Making Test (TMT), grooved pegboard, Controlled Oral Word Association Test (COWAT), Visual Form Discrimination, Wechsler Adult Intelligence Scale Revised (WAIS-R) (block design subtest), Rey Auditory Verbal Learning Test (RAVLT), Symbol Digit Modalities Test (), and Wisconsin Card Sorting Test (). The primary outcome measure was the level of supervision required after 1 year based on the Supervision Rating Scale (SRS). 3 Nearly all measures differentiated those needing supervision from those who did not on univariate analyses, however, only digits backward, COWAT, and predicted those needing moderate versus heavy supervision. Using a similar test battery, Ross et al 4 evaluated 59 patients enrolled in a TBIMS after resolution of posttraumatic amnesia (PTA). Although performance on no single measure was a significant predictor of psychosocial outcome on the Community Integration Questionnaire, 5 scores on the RAVLT, and TMT, when used in combination with age, significantly predicted home, and social integration. Performance on neuropsychologic tests have also been shown to be significantly correlated with severity of functional disability 6 and return to work. 7,8 Neese et al 6 investigated the association between various neuropsychologic testing domains (ie, intellectual, academic, language, visuoperceptual, memory, executive functioning) and level of functioning on the Disabil-

2 NEUROPSYCHOLOGIC BATTERY FOR PERSO WITH TBI, Hanks 951 ity Rating Scale (DRS). Participants completed the DRS and the neuropsychologic evaluation during postacute rehabilitation and composite scores were derived for each of the neuropsychologic domains. Results revealed a significant positive relationship between performance in intellectual, executive, academic, and visuoperceptual domains and level of disability on the DRS. Ruff et al 7 and others found that 3 measures, the Ruff2&7Test, 9 TMT (part B), and the vocabulary subtest of the WAIS-R, were significant predictors of return to work or school at 6 months postinjury. A second study completed by Cifu at al 8 using a similar test battery reported that only the logical memory subtest of the WMS-R predicted return to work at 1 year. It is important to note that neuropsychologic performance continues to be a significant predictor of later productivity even after controlling for the influence of demographic predictors and injury severity. 10,11 Over the last 10 years, market demands have increasingly required clinicians to establish prognoses earlier in the patient s course of recovery. This has given rise to new prognostic challenges because the average length of stay (LOS) for inpatient brain rehabilitation has fallen to 30 days. Historically, neuropsychologic assessment has been deferred until resolution of PTA to ensure that test scores reflect a valid estimation of patient abilities. 11 Consequently, most prior outcome studies have excluded data from persons who were in PTA or unable to complete neuropsychologic testing. This tradition is also problematic from a clinical perspective given that a significant percentage of patients with severe TBI do not attain the criteria for termination of PTA during acute rehabilitation and are discharged before formal neuropsychologic assessment can be conducted. As a result, neuropsychologic data are often unavailable when establishing prognosis early in the recovery course. 12 In view of the mandate to predict functional outcome early in the course of recovery, and mindful of the need to avoid selection bias brought about by excluding untestable patients from data analysis, we completed a prospective study of the predictive validity of performance on a brief neuropsychologic test battery administered at a fixed point during the subacute period of recovery, rather than after resolution of PTA. We hypothesized that neuropsychologic predictors would be significantly correlated with a range of functional outcomes, even when patients with ongoing PTA were retained in the dataset. METHODS Participants Five hundred forty-three TBIMS participants with mild complicated to severe TBI were screened with a brief neuropsychologic test battery at 7 TBIMS centers from July 1, 2004, through July 30, Of those 543 persons with TBI who were approached for testing, 239 of them completed the test battery in full. These participants were tested during their inpatient rehabilitation stay at 1 month postinjury. Criteria for the National Institute on Disability and Rehabilitation Research TBIMS program include: (1) medically documented TBI; (2) treatment at an affiliated level I trauma center within 24 hours of injury; (3) receipt of inpatient rehabilitation within the model system; (4) admission to inpatient rehabilitation within 72 hours of discharge from acute care; (5) age of at least 16 years at the time of injury; and (6) provision of informed consent by the person with injury or a legal proxy. 13 Additional inclusion criteria were initial rehabilitation hospitalization at 1 month postinjury ( 2wk; 14 42d postinjury) and emergence from minimally conscious state 14 or vegetative state. People were excluded who were (1) non-english speaking, (2) discharged from inpatient rehabilitation before 2 weeks postinjury, and (3) admitted for initial inpatient rehabilitation greater than 6 weeks postinjury. Due to attrition during the 1-year follow-up time period, only 176 of the 239 people who completed the inpatient neuropsychologic testing had 1-year outcome data, and this was the group of participants that we chose for analyses. Age of the participants ranged from years to (mean standard deviation [SD], ) and educational level ranged from 6 years to 19 years (mean, ). Race was reported to be 71% white, 23% black, 4% Hispanic, and 2% other. With respect to severity of TBI, Glasgow Coma Scale (GCS) scores ranged from 15 to 3 (median SD, ), although any scores in the 13 to 15 range reflected complicated mild cases in which there was evidence of intracranial bleed and the injury was severe enough to warrant an inpatient rehabilitation stay secondary to the TBI. Length of PTA for this group ranged from less than 1 day to 67 days (median, ). Data Collection Procedures This study was reviewed and approved by the institutional review boards at all participating institutions. Research assistants collected information regarding demographic characteristics (sex, race, years of education, age, preinjury employment status), cause of injury, injury severity (GCS scores at admission to emergency department), and PTA and LOS (acute care, rehabilitation) from hospital and emergency medical service records and from interview with participants and their family members. PTA was defined as the interval from injury until 2 consecutive scores of 76 or greater were obtained within a period of 24 to 72 hours 15 or the Orientation Log (score of 25). 16 To decrease the number of unknown durations of PTA for persons admitted to rehabilitation who were fully oriented, a chart review procedure was conducted to determine if there were 2 consecutive observations within a 24- to 72-hour period in which the person was determined to be oriented by 3 without interval notes denoting disorientation. All study participants were administered formal neuropsychologic testing at 1 month postinjury ( 2wk). The test battery was chosen based on previous research literature, which found these specific measures or measures with these cognitive domains to be predictive of outcome. Additionally, an attempt was made to include a test from the major domains of cognition that could be affected by TBI. The evaluation was attempted in 1 testing session and tests were administered using standardized protocols and given in the following sequence:, California Verbal Learning Test II (CVLT-II), TMT,, grooved pegboard test, phonemic and categorical word generation ( and animal naming), Wechsler Test of Adult Reading (WTAR), and 64 (see test descriptions below). All neuropsychologic tests were scored according to standardized instructions in their manuals, and T-score conversions were calculated based on the revised comprehensive norms for an Expanded Halstead-Reitan Battery 17 and the norms found in the manuals for the, CVLT-II, and WTAR (see below). As mentioned previously, although there was a larger group of over 500 people who were approached for testing, only 239 were able to complete the entire neuropsychologic test battery and only 176 of these had 1-year outcome data. Given the regression analyses used in this study, only those participants who had complete outcome data were included in the statistical analyses. Outcome measures were collected by research staff at all 7 centers at regularly scheduled TBIMS follow-up appointments at 1-year postinjury. The outcome measures included in this study were: the DRS, FIM instrument, SRS, Glasgow

3 952 NEUROPSYCHOLOGIC BATTERY FOR PERSO WITH TBI, Hanks Outcome Scale Extended (GOS-E), and the Satisfaction With Life Scale (SWLS) (see test descriptions below). For the sample included in this study, 77% of the patients who were able to complete the testing had cleared PTA, with a substantial number of patients (23%) still falling within the confused range. The 23% who were still confused were able to follow the instructions of the tasks and complete the battery without substantial difficulty. In the group that was not able to complete the test battery, 53% had cleared PTA. Neuropsychologic Measures Galveston Orientation and Amnesia Test. The is a 30-item measure of PTA that assesses orientation and memory for circumstances of injury. It has been shown to have good predictive validity for brain injury outcome. 15 The total errors score obtained during the testing at 1 month postinjury was used in regression analyses, as is common practice. Wechsler Test of Adult Reading. The WTAR is a measure of single-word reading that has been found to be a good estimate of premorbid intellectual functioning and has been shown to be predictive of outcome after TBI. 18,19 Symbol Digit Modalities Test. The 20 is a measure that captures a person s speed of information processing both motorically and orally. This test pairs 9 individual symbols with numbers (1 9), presented on a legend above the individual test items. The person must pair the number with the presented symbol as quickly as he/she can for a total test trial of 90 seconds. This is completed once through a written task (eg, the person writes the number below each symbol) and then again orally (eg, the person says each number as they scan each symbol). California Verbal Learning Test II. The CVLT-II 21 was used to assess new verbal learning and memory. This test measures verbal list learning and assesses acquisition, retention and storage, as well as retrieval and recognition of such information over both the short term and a 20-minute delay. The T score for total trials 1 through 5 was used in the regression analyses. Phonemic and categorical word generation ( and animal naming). This measure assesses cognitive initiation and interference control through phonemic and semantic word generation tasks from the Delis-Kaplan Executive Function System (DKEFS) battery. 22 T scores for the total words produced during these trials were included in the analyses. -64 card version. The is a measure of problem solving that uses examiner feedback to correct errors. This measure has been used in TBI quite extensively and the longer version of this measure has been shown to be predictive of functional outcome post-tbi. 18 The T score for perseverative responses was included in analyses. Trail-Making Test. The TMT 24 is a measure of visual conceptual and visuomotor tracking, attention, and maintenance of cognitive set-shifting. On part A, participants are instructed to connect the numbered circles in consecutive order by drawing a line between them as quickly as possible without lifting their pencil from the paper. On part B (TMT-B), participants are instructed to alternate between numbers and letters in order as quickly as possible. The score is the number of seconds it takes for completion of each part. The T score for total time for TMT-B was included in regression analyses. Outcome Measures Disability Rating Scale. The DRS 25,26 assesses the level of handicap with respect to basic and more complex activities, including employment. It has been shown to be related to neuropsychologic functioning during inpatient rehabilitation for TBI 18 and is a commonly used outcome measure in TBI research. Low scores on the DRS reflect a higher level of functioning, whereas higher scores reflect a lower level of functioning. For this study, DRS scores obtained by the inpatient rehabilitation treatment team at the time of admission, as well as the score obtained by TBIMS research staff at 1-year follow-up were used in data analyses. FIM instrument. The FIM instrument includes level of functional independence for both motor and cognitive tasks and is a well-established outcome measure and is given routinely on inpatient TBI units. There are 2 components, FIM motor and FIM cognitive, that reflect motor and cognitive functioning respectively. This measure was administered during the inpatient rehabilitation stay as well as at 1-year follow-up. The FIM instrument has been shown to be related to cognitive functioning after TBI. 18 Glasgow Outcome Scale Extended. The GOS-E 27 is based on a brief structured interview and provides a single score from 1 to 8 indicating the global outcome of injury, from death to very favorable recovery. For this project, the single score was used in data analysis. Supervision Rating Scale. The SRS 3 rates the level of supervision that a person receives from his/her caregivers. Level of supervision is ranged on a 13-point ordinal scale that is then classified into 5 more general levels of supervision (ie, independent, overnight supervision, part-time supervision, fulltime indirect supervision, full-time direct supervision). Ratings are based on level of supervision received, not necessarily how much supervision is thought to be needed by the person completing the form. A lower score reflects more independence and a higher score reports a greater amount of supervision. Satisfaction With Life Scale. The SWLS 28 is a self-report measure in which respondents indicate their degree of agreement with 5 statements about life satisfaction, for example, In most ways my life is close to my ideal ; If I could live my life over, I would change almost nothing. Scores range from 5 (low satisfaction) to 35 (high satisfaction), and a total score, which reflects the sum of all 5 items, was used in data analyses for this project. Statistical Analyses To assess the predictive validity of the neuropsychologic tests with respect to functional outcomes, we used multiple regression analyses. An important question for this study was whether the neuropsychologic tests predicted outcomes at 1 year above and beyond functional variables and injury severity characteristics. For this reason, time to follow command, which is defined as the number of days that it takes to obtain a score of 6 on the motor subscale of the GCS, admission DRS score, and admission FIM score was entered into the regression in 1 block, followed by the neuropsychologic variables in the second block. RESULTS Prediction of Level of Handicap As shown in table 1, the combination of injury severity and functional variables at time of admission to rehabilitation predicted the level of handicap at 1 year postinjury (.06, P.02). Only the FIM total score at inpatient rehabilitation admission was a significant predictor (P.05), and it accounted for 2% of the unique variance. The addition of the neuropsychologic variables, as a group, were found to add to incremental validity to the prediction of level of handicap at 1 year (

4 NEUROPSYCHOLOGIC BATTERY FOR PERSO WITH TBI, Hanks 953 Table 1: Prediction of Level of Handicap as Measured by the Disability Rating Scale at 1 Year , ND ND Admission FIM Admission DRS Time to follow commands Neuropsychologic variables , CVLT-II TMT-B.065 WTAR NOTE. CVLT-II total score is for trials 1 5; grooved pegboard times for the dominant hand;, total score is for written trials; scores are perseverative responses; animal naming and category fluency are from the DKEFS. Abbreviations: ND, no data;, nonsignificant. change,.16; P.000); but only the estimate of premorbid intellectual functioning, the WTAR scaled score was a significant predictor on its own (P.000), accounting for approximately 9% of the variance. TMT-B approached significance (P.065). Functional Independence As shown in table 2, injury severity and the functional variables at admission to inpatient rehabilitation as a group did not predict FIM total at 1 year postinjury; however, the FIM score at admission approached significance (P.085). When the neuropsychologic measures were added to the equation, the model became statistically significant ( change,.12; P.014), and TMT-B and the WTAR were identified as statistically significant predictors accounting for approximately 5% and 3% of unique variance in functional independence at 1 year postinjury, respectively. When FIM cognitive scores were examined, the first block was found to be a significant predictor (.107, P.000), and the total DRS score at inpatient rehabilitation admission was a significant predictor (P.013), accounting for 3% of the variance (table 3). With the addition of the neuropsychologic test scores, the model was again statistically significant ( change,.15; P.001), and TMT-B and the WTAR were significant predictors accounting for 2.5% and 5% of the variance, respectively. Neither the injury severity, functional measures at inpatient rehabilitation admission, nor the neuropsychologic measures were significant predictors of FIM motor scores at 1 Table 2: Prediction of Functional Independence (FIM total) at 1 Year , ND ND Admission FIM.085 Admission DRS Time to follow commands Neuropsychologic variables , CVLT-II TMT-B WTAR NOTE. See table 1 legend.

5 954 NEUROPSYCHOLOGIC BATTERY FOR PERSO WITH TBI, Hanks Table 3: Prediction of Functional Independence in Cognitive Domains (FIM cognitive) at 1 Year , ND ND Admission FIM Admission DRS Time to follow commands Neuropsychologic variables , CVLT-II TMT-B WTAR NOTE. See table 1 legend. year postinjury, but TMT-B on its own was a significant predictor (P.013) accounting for approximately 3.5% of unique variance. Level of Supervision The amount of supervision that the persons with TBI received at 1 year postinjury was not predicted well by the injury severity and functional measures, but when the neuropsychologic test data were added to the equation the model became significant as shown in table 4 ( change,.11; P.023). The only significant predictor was estimated premorbid IQ based on the WTAR score (P.035), which accounted for approximately 2.5% of the unique variance. Satisfaction With Life Subjective quality of life was not predicted by either the group of injury severity and functional variables (P.53), or the neuropsychologic test battery administered during inpatient rehabilitation (P.312). Interestingly, there were no significant predictors in either of these 2 groups of variables. Overall Level of Functioning 1 Year After Brain Injury Injury severity, functional, and neuropsychologic test variables were regressed on the total score of the GOS-E as shown in table 5. Again, the first group of variables consisted of time to follow command and functional indices at Table 4: Prediction of Level of Supervision as Measured by the SRS at 1 Year , ND ND Admission FIM Admission DRS Time to follow commands Neuropsychologic variables , CVLT-2 TMT-B WTAR NOTE. See table 1 legend.

6 NEUROPSYCHOLOGIC BATTERY FOR PERSO WITH TBI, Hanks 955 Table 5: Prediction of Global Functioning as Measured by the GOS-E at 1 Year , ND ND Admission FIM Admission DRS Time to follow commands Neuropsychologic variables , CVLT-2 TMT-B WTAR NOTE. See table 1 legend. admission to inpatient rehabilitation services. This group of variables was not found to be predictive, although when the neuropsychologic test variables were added to the equation the model became statistically significant ( change,.11; P.022). As is consistent with many of the other regression analyses in this study, the only independent or unique predictor of outcome was TMT-B (P.046), which accounted for 2% of the variance. DISCUSSION The present findings indicate that a brief battery of standardized neuropsychologic tests administered during inpatient rehabilitation within 1 month ( 2wk) of injury predicts handicap, functional outcome, supervision needs, and employability at 1 year in adults with TBI. With only 2 exceptions (ie, subjective quality of life, as measured by the SWLS and FIM motor scores), adding the battery of neuropsychologic tests increased significant predictive power over injury severity and early functional status in predicting outcomes at 1 year. Overall, these data provide support for the validity of routine inpatient neuropsychologic screening for persons with TBI. Although previous research has certainly also supported the use of early neuropsychologic testing in predicting specific aspects of outcome at 1 year, 1,11,29 the present study builds on such literature by providing a prospective design, greater specificity in the timing of testing, and evaluation of a wide variety of outcome variables. The fact that persons still in PTA were included in the analyses presented a novel opportunity to examine outcomes across a wider continuum of injury recovery than in previous studies and increased the generalizability of the findings. As we pointed out above, previous studies have not included persons in PTA, thus effectively reducing the numbers of persons that could be studied, based on an a priori assumption (ie, that test results would be invalidated by PTA) rather than on empirical data. In the present sample, it appears that the inclusion of persons in PTA does not diminish the predictive validity of the model. This is an important finding, because it argues for the role of neuropsychologic testing even during the acute rehabilitation phase. This finding could also increase the number of persons receiving neuropsychologic testing in both research and clinical contexts persons who might not have been tested in the past, given an assumption that their test results would be invalid. Finally, having support for testing persons in PTA has become increasingly necessary in light of more acute admissions and shorter rehabilitation stays given that the number of persons enrolled in TBI rehabilitation and remaining in PTA for much (or the duration) of their stay is increasingly likely. Initial injury severity and functional status on rehabilitation admission were generally poor predictors across most of the domains of outcome assessed. This is not surprising given that many persons with TBI will show a restricted range of responsiveness and abilities in the acute phase, but may show a much wider range of presentations during the course of their rehabilitation stay. In addition, the dependence on cognitive functioning in the achievement of functional outcomes, and the emphasis of cognition on many of the outcome scales used (eg, the DRS), make it quite likely that cognitively based measures will give greater predictive validity than measures that rely more on sensorimotor responsiveness or activities of daily living that cannot be safely attempted or successfully performed prior to receiving rehabilitation services. Collectively, the present battery of tests added to the predictive models, but there were also individual tests that had unique predictive power for outcomes at 1 year postinjury. TMT-B was a significant independent predictor of functional independence (FIM) and general outcome (GOS-E), and was also a strong though not statistically significant predictor of handicap (DRS). This is not surprising given that TMT-B assesses a variety of important executive control and other processes including sequencing, set alternation, and psychomotor speed and has been repeatedly shown to be robustly correlated with a variety of variables after TBI. 18 Interestingly, the measure used to estimate premorbid cognitive status or cognitive reserve the WTAR emerged as the test that was individually the most predictive of 1-year outcomes, contributing unique variance to the model in the prediction of handicap (DRS), functional independence (FIM), supervision level (SRS), and employability. The importance of cognitive reserve has been discussed in a variety of clinical

7 956 NEUROPSYCHOLOGIC BATTERY FOR PERSO WITH TBI, Hanks populations, and has received recent attention in the TBI literature. 18,30-32 This finding in the present sample strongly suggests that having an accurate assessment of cognitive reserve is important in the prediction of outcomes, and is a potentially unique contribution that could be made from neuropsychologic assessment. Study Limitations The present findings are encouraging, but some limitations must be recognized. This study was conducted within the National Institute on Disability Rehabilitation Research TBIMS. Given that programs must meet certain criteria (eg, adequate patient flow; an integrated system of care from the emergency department through community reintegration; research infrastructure) and must provide a comprehensive continuum of TBI rehabilitation services to even be selected as a model system center, these findings might not generalize to facilities with fewer services (eg, lack of on-site neuropsychology staff) or resources. The present tests were selected based on their representation of core cognitive impairments in persons with TBI and their use in prior studies, yet it must be recognized that other tests from the presently selected cognitive domains may have greater predictive validity, as might tests that tap other constructs altogether (eg, working memory). Additional research examining other cognitive domains, or more specific aspects of certain cognitive domains, is warranted in future research. Additionally, the neuroanatomic correlates of such cognitive domains would be of interest from a research perspective, as injuries to certain neuronal substrates (eg, frontal subcortical circuits) may have a greater impact on outcome measures, not to mention performance on a specific subset of neuropsychologic tests. Future studies using this battery may wish to consider different outcome variables. The present study used well standardized outcomes rating scales, all of which have been used extensively in the TBI literature, but additional research is needed to determine if early inpatient neuropsychologic testing predicts to other outcomes domains (eg, community integration and participation), to more detailed functional outcome measures (eg, the Craig Handicap Assessment Reporting Technique), or to behaviorally anchored outcome variables (eg, hours worked a week, job or school performance, or performance on structured functional tasks). CONCLUSIO The results of this study support the clinical utility and ecological validity of a brief battery of cognitive tests for persons who are receiving inpatient rehabilitation for TBI. This battery appears to be useful for the prediction of level of disability and functional independence, and the amount of supervision required. Given the findings that measures of premorbid intellectual functioning (WTAR) and executive functioning (TMT-B) were particularly strong predictors of outcome, it is recommended that cognitive test batteries that are used to assess people with TBI consider inclusion of these types of measures. References 1. Sherer M, Novack TA, Sander AM, Struchen MA, Alderson A, Thompson RN. Neuropsychological assessment and employment outcome after traumatic brain injury: a review. Clin Neuropsychol 2002;16: Hart T, Millis S, Novack T, Englander J, Fidler-Sheppard R, Bell KR. 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