Jomana Amara

Testing for Purchasing Power Parity using stationary covariates

Purchasing Power Parity is tested for in post-Bretton Woods real exchange rate data from 20 developed countries using univariate tests and covariate augmented versions of the Augmented Dickey–Fuller (CADF) and feasible point optimal (CPT) unit root tests. The covariates are a combination of stationary variables – inflation, monetary, income, and current account. A cross method comparison of the results is performed. Very strong evidence is found of PPP using the CPT test, rejecting the unit root null for 12 out of the 20 countries at the 5% significance level or better, and six more at the 10% level. Much less evidence is found of PPP with the CADF and univariate tests.

Prevalence of dual sensory impairment and its association with traumatic brain injury and blast exposure in OEF/OIF Veterans

Objective:To describe the prevalence of self-reported rates of auditory, visual, and dual sensory impairment (DSI) in Afghanistan and Iraq war Veterans receiving traumatic brain injury (TBI) evaluations. Design:Retrospective medical chart review. Participants:Thirty-six thousand nine hundred nineteen Veterans who received a TBI evaluation between October 2007 and June 2009. Final sample included 12,521 subjects judged to have deployment-related TBI and a comparison group of 9106 participants with no evidence of TBI. Main Outcome Measure:Self-reported auditory and visual impairment. Results:Self-reported sensory impairment rates were: 34.6% for DSI, 31.3% for auditory impairment only, 9.9% for visual impairment only, and 24.2% for none/mild sensory impairment. Those with TBI and blast exposure had highest rate of DSI. Regression analyses showed that auditory impairment was the strongest predictor of visual impairment, and vice versa, suggesting these impairments may derive from a common source. Conclusions:Veterans who self-report clinically significant hearing or vision difficulty during routine TBI evaluation should be evaluated systematically and comprehensively to determine the extent of sensory impairment. Identifying DSI could allow clinicians to collaborate and maximize rehabilitation.

Screening for mild traumatic brain injury in OEF-OIF deployed US military: An empirical assessment of VHA's experience

Background: VHA screens for traumatic brain injury (TBI) among patients formerly deployed to Afghanistan or Iraq, referring those who screen positive for a Comprehensive TBI Evaluation (CTBIE). Methods: To assess the programme, rates were calculated of positive screens for potential TBI in the population of patients screened in VHA between October 2007 through March 2009. Rates were derived of TBI confirmed by comprehensive evaluations from October 2008 through July 2009. Patient characteristics were obtained from Department of Defense and VHA administrative data. Results: In the study population, 21.6% screened positive for potential TBI and 54.6% of these had electronic records of a CTBIE. Of those with CTBIE records, evaluators confirmed TBI in 57.7%, yielding a best estimate that 6.8% of all those screened were confirmed to have TBI. Three quarters of all screened patients and virtually all those evaluated (whether TBI was confirmed or not) had VHA care the following year. Conclusions: VHAs TBI screening process is inclusive and has utility in referring patients with current symptoms to appropriate care. More than 90% of those evaluated received further VHA care and confirmatory evaluations were associated with significantly higher average utilization. Generalizability is limited to those who seek VHA healthcare.

Associations Between Traumatic Brain Injury, Suspected Psychiatric Conditions, and Unemployment in Operation Enduring Freedom/Operation Iraqi Freedom Veterans.

Objective:To examine the relations among demographic characteristics, traumatic brain injury (TBI) history, suspected psychiatric conditions, current neurobehavioral health symptoms, and employment status in Veterans evaluated for TBI in the Department of Veterans Affairs. Study Design:Retrospective cross-sectional database review of comprehensive TBI evaluations documented between October 2007 and June 2009. Participants:Operation Enduring Freedom/Operation Iraqi Freedom Veterans (n = 11 683) who completed a comprehensive TBI evaluation. Main Measures:Veterans Affairs clinicians use the comprehensive TBI evaluations to obtain information about TBI-related experiences, current neurobehavioral symptoms, and to identify suspected psychiatric conditions. Results:Approximately one-third of Veterans in this sample were unemployed, and of these, the majority were looking for work. After simultaneously adjusting for health and deployment-related variables, significant factors associated with unemployment included one or more suspected psychiatric conditions (eg, posttraumatic stress disorder, anxiety, depression), neurobehavioral symptom severity (ie, affective, cognitive, vestibular), former active duty status, injury etiology, age, lower education, and marital status. The associations of these factors with employment status varied by deployment-related TBI severity. Conclusions:Simultaneously addressing health-related, educational, and/or vocational needs may fill a critical gap for helping Veterans readjust to civilian life and achieve their academic and vocational potential.

Determinants of utilization and cost of VHA care by OEF/OIF Veterans screened for mild traumatic brain injury.

OBJECTIVE To determine the demographic and service characteristics that differentially impact utilization and cost of Veterans Health Administration (VHA) services for Operation Enduring Freedom and Operation Iraq Freedom (OEF/OIF) Veterans screened or evaluated for traumatic brain injury (TBI). SETTING We examined Department of Defense (DoD) and VHA administrative records of OEF/OIF Veterans who were screened or evaluated for TBI. PARTICIPANTS Our study population was OEF/OIF Veterans who separated from DoD in Fiscal Years 2003-2009 and who were screened or evaluated in VHA for TBI between October 2008 and July 2009. DESIGN We describe the demographics and service characteristics of separated Veterans and those who accessed the VHA. We report the cost of VHA utilization and estimate a probit regression model to assess determinants of VHA utilization and costs by OEF/OIF Veterans screened and evaluated for TBI by VHA. RESULTS Females and Veterans older than 37 years utilize VHA services more intensely. Across all services, the Reserve Components utilize health services more than the Active Components placing more demand on VHA for services. CONCLUSION VHA utilization and costs is impacted by the demographic and service characteristics of Veterans. The variation in Veteran groups incurring higher costs and utilization indicates different usage patterns of VHA services by each group with implications for patient load as the DoD deploys higher numbers of females and the Reserve Components.

Concordance of Clinician Judgment of Mild Traumatic Brain Injury History with a Diagnostic Standard

The concordance of Department of Veterans Affairs (VA) clinician judgment of mild traumatic brain injury (mTBI) history with American Congress of Rehabilitation Medicine (ACRM)-based criteria was examined for Operation Iraqi Freedom (OIF) and Operation Enduring Freedom (OEF) Veterans. In order to understand inconsistencies in agreement, we also examined the associations between evaluation outcomes and conceptually relevant patient characteristics, deployment-related events, current self-reported health symptoms, and suspected psychiatric conditions. The Veteran sample comprised 14,026 OIF/OEF VA patients with deployment-related mTBI history (n = 9,858) or no history of mTBI (n = 4,168) as defined by ACRM-based criteria. In the majority of cases (76.0%), clinician judgment was in agreement with the ACRM-based criteria. The most common inconsistency was between clinician judgment (no) and ACRM-based criteria (yes) for 21.3% of the patients. Injury etiology, current self-reported health symptoms, and suspected psychiatric conditions were additional factors associated with clinician diagnosis and ACRM-based criteria disagreement. Adherence to established diagnostic guidelines is essential for accurate determination of mTBI history and for understanding the extent to which mTBI symptoms resolve or persist over time in OIF/OEF Veterans.

Testing for stationarity using covariates: an application to purchasing power parity

We examine the evidence for Purchasing Power Parity (PPP) using post-Bretton Woods exchange rate data for 20 industrialized countries. The two tests used are the covariate tests for stationarity where the null hypothesis of stationarity is tested against the unit root alternative. These tests are generalizations of existing univariate stationarity tests and improve the power of univariate tests by utilizing the information contained in related stationary covariates. We conclude that PPP holds for 17 out of the 20 countries tested.

NATO Defense Expenditures: Common Goals or Diverging Interests? A Structural Analysis

By testing for structural breaks in defense expenditures, the dates of change in the pattern of defense expenditures for the NATO allies are determined. If NATO members are responding to a common threat, the breaks should be similar, in both direction and dates, for defense expenditures. The breaks should occur during major NATO strategy shifts. The results of the structural analysis tests suggest that NATO allies do not have an integrated response to NATO‐specific defense issues. It appears that NATO members, in general, adjusted their defense spending according to economic imperatives, political issues, and ally‐specific defense agendas.

EVALUATING NATO LONG RUN DEFENSE BURDENS USING UNIT ROOT TESTS

This study evaluates NATO long run defense burdens by analyzing the time‐series properties of burden measures, namely growth of defense spending, defense share in national output, defense share in government spending, defense spending per capita, and defense share in total NATO spending for the time period 1949–2002. The study also compares the effect of using government Purchasing Power Parity conversion factors and Market Exchange Rates for defense share in total NATO expenditure conversions and the implications of NATO expansion in light of the defense burden measures of the newer NATO members.

Military and Veterans’ Health, Health Care, and Wellbeing

Abstract The U.S. Department of Defense (DoD) and the U.S. Department of Veterans Affairs (VA) need to bridge a gap in their understanding of service members’ health outcomes and the issues involved in treatment, such as cost. In addition, clinicians and policy analysts must overcome existing knowledge barriers. Clinicians need to be aware of policy changes that will affect their patient load in numbers and in treatment needs. Policy analysts need to be aware of issues relevant to clinical treatment, such as quality and timeliness of care. Given the need for services and support to military personnel and families, and the fact that the fastest growing expenses in defense are health care costs, a multi-disciplinary line of research will help lawmakers understand the most efficient and effective resource use across the health care services.