The Reliability and Validity of the Neurological Outcome Scale for Traumatic Brain Injury (NOS-TBI) in Persons with Post-Acute Traumatic Brain Injury (TBI) and Healthy Control Participants K. H. Holley 1, P. T. Roskos 1,2, K. Lindsay 3, J. D. Gfeller 2, & R. D. Bucholz 1 1 Department of Neurosurgery 2 Department of Psychology, 3 Department of Surgery Saint Louis University, St. Louis, Missouri, USA Conclusion Results indicated the NOS-TBI is a reliable (i.e. internally consistent) and valid measure of TBI outcome functioning, showing that it assesses a related, but unique, construct compared to other instruments. The NOS-TBI has significant convergent validity with other outcome measures and related neuropsychological tests. In our post-acute TBI sample, the NOS-TBI appeared most sensitive to neurologic deficits in patients with sever TBI. The findings suggest that the NOS-TBI has promise as a measure that complements other TBI outcome instruments. Overview The Neurological Outcome Scale for Traumatic Brain Injury (NOS-TBI; Wilde et. al., 2010) is a multidimensional 15-item scale designed to measure neurological deficits following traumatic brain injury (TBI). Derived from the NIH Stroke Scale, it incorporates basic elements of a clinical neurological examination, including orientation, cranial nerve functioning, strength, sensation, language, and coordination. Studies conducted by the NOS-TBI authors indicated the inventory has adequate psychometric properties in acute TBI participants. This study further examined the psychometrics of the NOS-TBI using a community sample of individuals with post-acute TBI and healthy control participants. Based on previous literature, adequate reliability and validity would be anticipated. Furthermore, this study sought to determine the inventory’s effectiveness in distinguishing individuals with TBI and healthy controls. Differences in NOS-TBI scores between control participants and mild, moderate, and severe TBI participants were expected. Method As part of a larger ongoing prospective study, data were collected from 28 healthy controls and 49 individuals with a history of TBI (30 mild TBI, 10 moderate TBI, 9 severe TBI). Healthy controls were recruited from the surrounding metropolitan area. Civilians with TBI were drawn from a large urban hospital and its catchment area, while veterans with TBI were recruited nationally. The mean age of participants in the TBI and normal groups (31.73 versus years) did not differ significantly [F (1,75) = 1.48, p =.23]. Participants in both groups were predominantly male (95%) and Caucasian (78%). Participants were mostly right handed (82%). The TBI group was slightly less well educated (13.65 years vs years) relative to the healthy control participants [F(1,75) = 7.90, p <.01]. TBI participants were greater than 6-months post- injury at the time of evaluation, with a mean of 4.55 years. All participants were administered the NOS-TBI in addition to other outcome inventories, including the Galveston Orientation & Amnesia Test (GOAT), Ranchos Los Amigos Levels of Cognitive Functioning Scale (LOCF), Disability Rating Scale (DRS), Community Integration Questionnaire (CIQ), Glasgow Coma Scale (GCS), Modified Rankin Scale (MRS), and the Glasgow Outcome Scale Extended (GOSE). Additionally, all participants completed a battery of neuropsychological tests that included selected subtests from the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS Form A Language Index), selected subtests from the Wechsler Adult Intelligence Scale Third Edition (WAIS-III Digit Span, Block Design), California Verbal Learning Test Second Edition (CVLT-II), Wechsler Test of Adult Reading (WTAR), Verbal Fluency from the Delis Kaplan Executive Functioning System (DKEFS VF), and the Grooved Pegboard Test (GPT). Internal consistency reliability (Cronbach’s alpha) was calculated for the NOS-TBI. Spearman correlation analyses were also conducted to determine the association between the NOS-TBI, other TBI outcome measures, and neuropsychological tests. Additionally, ANOVA was performed to determine if differences exist between the healthy control, mild, moderate, and severe TBI groups based on NOS-TBI total scores. Results Internal consistency of the NOS-TBI was found to be high (Cronbach’s alpha=.80). The NOS-TBI had multiple significant correlations (ranging from -.60 to.41) with other outcome measures used in TBI (e.g. DRS, CIQ, and neuropsychological tests) in the expected directions. Results from these analyses are presented in the Table. The notable patterns among the correlations are described as follows:  The NOS-TBI showed significant medium magnitude correlations with the DRS, GOAT, CIQ and LOCF scales, but did not correlate significantly with current GCS, MRS, or GOSE scores. Significant correlations were found between the NOS-TBI and measures used to assess orientation, cognitive/physical disability, and community functioning.  NOS-TBI scores also significantly correlated with a number of neuropsychological tests representing cognitive domains commonly affected by TBI (learning and memory, attention and processing speed, executive functioning, and language skills). It did not correlate significantly with estimated intellectual functioning (WTAR) or fine motor skills. ANOVA analyses showed that NOS-TBI scores were significantly higher in the TBI participants compared to controls [F (1,75) = 6.53, p <.05]. Tukey HSD post-hoc analyses indicated that the severe TBI group (M = 5.00, SD = 3.57 ) had significantly higher scores than the other three groups: healthy controls (M =.464, SD =.51), Mild TBI (M =.833, SD =.83), and Moderate TBI (M = 1.30, SD = 2.54), p <.001. Statistically significant differences were not observed between the healthy controls, mild TBI, and moderate TBI groups on NOS-TBI scores. These null results may be a function of the post-acute nature of the TBI sample in which the mean time post injury was 4.55 years. As expected, persons with the most enduring neurological deficits were those who initially had severe TBI. ANOVA results and mean scores on the NOS-TBI for each of the groups are displayed in the Figure. Funding Acknowledgment This research was supported by the following grant from the Department of Defense: Evidence-Based Multimodal Neurodiagnostic Imaging of Traumatic Brain Injury and Post-Traumatic Stress Disorder at SANIC; Award Number W 81XWH , Richard Bucholz, Principle Investigator. Correspondence: P. Tyler Roskos, PhD, ABPP, Department of Neurosurgery, Saint Louis University, Presented at the 40 th Annual Meeting of the International Neuropsychological Society, Montreal, CA (2/2012). Figure. Mean NOS-TBI Total Scores for each of the groups Table. Spearman-ϱ Correlations TBI Outcome ScalesNOS-TBI Total Score GOAT Total Score-.318** LOCF Total Score-.330* DRS Total Score.412** CIQ Total Score-.271* GCS Total Score-.185 MRS Total Score.210 GOSE Total Score.192 Neuropsychological Tests RBANS Language Index Score-.234* WAIS-III Digit Span Scaled Score-.378** WAIS-III Block Design Scaled Score-.297* CVLT-II Trials 1-5 Total T-Score-.603** DKEFS VF Condition 1 Scaled Score-.315** WTAR Scaled Score-.195 GPT Dominant Hand T-Score-.154 GPT Non-Dominant Hand T-Score-.146 Significant correlations are bolded. *p <.05 (two-tailed); ** p <.01 (two-tailed).