Background. Dizziness is one of the most common symptoms in primary care and the most frequent comorbidity of mild traumatic brain injury (mTBI) followed by headache [1-3]. Vertigo and dizziness are predictors of headache persistence [4]. Vestibular rehabilitation is one of the most important and successful treatment modalities for patients with mTBI. Significance/Impact. The challenge this project addresses is translation of this knowledge from the specialized facility to the community level where most Veterans with mTBI reside. The proposed research project addresses HSR&D Research Priority Topics including the use of healthcare informatics to improve access to care and the examination of models of service delivery and care management that promote optimal recovery, rehabilitation, and reintegration for TBI. The long-term goal of this program of research is to improve access to and quality of health care for Veterans with TBI-related vestibular disorders. Innovation. The short-term goals are to examine utilization of VA services by Veterans who report dizziness (national level data) and to determine if the treatment provided is effective (local level data). Specific Aims. The Aims are to: (1) Determine, using national data, the utilization of VA services by OEF/OIF patients who report dizziness symptoms, (2) Determine, using local Post-Deployment Rehabilitation & Evaluation Program (PREP) data, predictors of severity of vestibular dysfunction and factors that influence the effectiveness of vestibular rehabilitation, and (3) Increase the capacity to reliably measure the effectiveness of vestibular rehabilitation for individuals with mTBI. Methodology. Aim 1 uses a retrospective, big data design and national Comprehensive Traumatic Brain Injury Level II Examination data. Frequencies of the different types of referral recommendations made and follow up visits will be tabulated. Logistic regression analysis will be used to identify Veteran, clinician, and system-level factors associated with patient likelihood of receiving a referral and following up with the referral. Aim 2 will use a retrospective design and local (Tampa PREP) data to conduct an uncontrolled exploration of the magnitude of change associated with vestibular rehabilitation. Postural stability, balance, self-perceived dizziness handicap, post-concussive symptoms, and gaze stabilization outcome measures will be evaluated using multiple linear regression. The percentage of variance explained will be calculated for all models and compared to identify which vestibular rehabilitation outcome variable appears to be best explained by a set of patient, clinician, and system level predictors. Aim 3 will use Aim 2 data to evaluate the psychometric properties and responsiveness or clinical sensitivity to change of selected vestibular function measures for the TBI-related vestibular dysfunction population. If the aims of this project are achieved, the following will be identified: (1a) the numbe...