Search results

Measures used to protect subjects in publicly distributed microdata files often have a significant negative impact on key analytic uses of the data. For example, it may be important to analyze subpopulations within a data file such as racial minorities, yet these subjects may present the greatest disclosure risk because their records tend to stand out or be unique. Files or records that are linkable create another type of disclosure risk—common elements between two files can be used to link files with sensitive data to externally available files that disclose identity. Examples of disclosure limitation methods used to address these types of issues include blanking out data, coarsening response categories, or withholding data altogether. However, the very detail that creates the greatest risk also provides insight into differences that are of greatest interest to analysts. Restricted-use agreements that provide unaltered versions of the data may not be available, or only selectively so. The public-use version of the data is very important because it is likely to be the only one to which most researchers, policy analysts, teaching faculty, and students will ever have access. Hence, it is the version from which much of the utility of the data is extracted and often it effectively becomes the historical record of the data collection. This underscores the importance that the disclosure review committee strikes a good balance between protection and utility. In this paper we describe our disclosure review committee's (DRC) analysis and resulting data protection plans for two national studies and one administrative data system. Three distinct disclosure limitation methods were employed, taking key uses of the data into consideration, to protect respondents while still providing statistically accurate and highly useful public-use data. The techniques include data swapping, microaggregation, and suppression of detailed geographic data. We describe the characteristics of the data sets that led to the selection of these methods, provide measures of the statistical impact, and give details of their implementations so that others may also utilize them. We briefly discuss the composition of our DRC, highlighting what we believe to be the important disciplines and experience represented by the group.

BACKGROUND: Investigations of drinking behavior across military deployment cycles are scarce, and few prospective studies have examined risk factors for post-deployment alcohol misuse. METHODS: Prevalence of alcohol misuse was estimated among 4,645 U.S. Army soldiers who participated in a longitudinal survey. Assessment occurred 1–2 months before soldiers deployed to Afghanistan in 2012 (T0), upon their return to the U.S. (T1), 3 months later (T2), and 9 months later (T3). Weights-adjusted logistic regression was used to evaluate associations of hypothesized risk factors with post-deployment incidence and persistence of heavy drinking (consuming 5+ alcoholic drinks at least 1–2×/week) and Alcohol or Substance Use Disorder (AUD/SUD). RESULTS: Prevalence of past-month heavy drinking at T0, T2, and T3 was 23.3% (SE=0.7%), 26.1% (SE=0.8%), and 22.3% (SE=0.7%); corresponding estimates for any binge drinking were 52.5% (SE=1.0%), 52.5% (SE=1.0%), and 41.3% (SE=0.9%). Greater personal life stress during deployment (e.g., relationship, family, or financial problems) – but not combat stress – was associated with new onset of heavy drinking at T2 [per standard score increase: AOR=1.20, 95% CI 1.06–1.35, p=.003]; incidence of AUD/SUD at T2 (AOR=1.54, 95% CI 1.25–1.89, p<.0005); and persistence of AUD/SUD at T2 and T3 (AOR=1.30, 95% CI 1.08–1.56, p=.005). Any binge drinking pre-deployment was associated with post-deployment onset of HD (AOR=3.21, 95% CI 2.57–4.02, p<.0005) and AUD/SUD (AOR=1.85, 95% CI 1.27–2.70, p=.001). CONCLUSIONS: Alcohol misuse is common during the months preceding and following deployment. Timely intervention aimed at alleviating/managing personal stressors or curbing risky drinking might reduce risk of alcohol-related problems post-deployment.

Traumatic brain injury (TBI) contributes to the increased rates of suicide and post-traumatic stress disorder in military personnel and veterans, and it is also associated with the risk for neurodegenerative and psychiatric disorders. A cross-phenotype high-resolution polygenic risk score (PRS) analysis of persistent post-concussive symptoms (PCS) was conducted in 845 U.S. Army soldiers who sustained TBI during their deployment. We used a prospective longitudinal survey of three brigade combat teams to assess deployment-acquired TBI and persistent physical, cognitive, and emotional PCS. PRS was derived from summary statistics of large genome-wide association studies of Alzheimer's disease, Parkinson's disease, schizophrenia, bipolar disorder, and major depressive disorder (MDD); and for years of schooling, college completion, childhood intelligence, infant head circumference (IHC), and adult intracranial volume. Although our study had more than 95% of statistical power to detect moderate-to-large effect sizes, no association was observed with neurodegenerative and psychiatric disorders, suggesting that persistent PCS does not share genetic components with these traits to a moderate-to-large degree. We observed a significant finding: subjects with high IHC PRS recovered better from cognitive/emotional persistent PCS than the other individuals (R2 = 1.11%; p = 3.37 × 10−3). Enrichment analysis identified two significant Gene Ontology (GO) terms related to this result: GO:0050839∼Cell adhesion molecule binding (p = 8.9 × 10−6) and GO:0050905∼Neuromuscular process (p = 9.8 × 10−5). In summary, our study indicated that the genetic predisposition to persistent PCS after TBI does not have substantial overlap with neurodegenerative and psychiatric diseases, but mechanisms related to early brain growth may be involved.

The Army Study to Assess Risk and Resilience in Servicemembers (Army STARRS) is a research project aimed at identifying risk and protective factors for suicide and related mental health outcomes among Army Soldiers. The New Soldier Study component of Army STARRS included the assessment of a range of cognitive and emotion processing domains linked to brain systems related to suicidal behavior including PTSD, mood disorders, substance use disorders, and impulsivity. We describe the design and application of the Army STARRS neurocognitive test battery to a sample of 56,824 soldiers. We investigate its structural and concurrent validity through factor analysis and correlation of scores with demographics. We conclude that, in addition to being composed of previously well-validated measures, the Army STARRS neurocognitive battery as a whole demonstrates good psychometric properties. Correlations of scores with age and sex differences mostly replicate previously published findings, highlighting moderate to large effect sizes even within this restricted age range. Factor structures of scores conform to theoretical expectations. This neurocognitive battery provides a brief, valid measurement of neurocognition that may be helpful in predicting mental health and military performance. These measures can be integrated with neuroimaging to offer a powerful tool for assessing neurocognition in Servicemembers.

Mild traumatic brain injury (mTBI), or concussion, is prevalent in the military. The course of recovery can be highly variable. This study investigates whether deployment-acquired mTBI is associated with subsequent presence and severity of post-concussive symptoms (PCS) and identifies predictors of persistent PCS among US Army personnel who sustained mTBI while deployed to Afghanistan. We used data from a prospective longitudinal survey of soldiers assessed 1–2 months before a 10-month deployment to Afghanistan (T0), on redeployment to the United States (T1), approximately 3 months later (T2), and approximately 9 months later (T3). Outcomes of interest were PCS at T2 and T3. Predictors considered were: sociodemographic factors, number of previous deployments, pre-deployment mental health and TBI history, and mTBI and other military-related stress during the index deployment. The study sample comprised 4518 soldiers, 822 (18.2%) of whom experienced mTBI during the index deployment. After adjusting for demographic, clinical, and deployment-related factors, deployment-acquired mTBI was associated with nearly triple the risk of reporting any PCS and with increased severity of PCS when symptoms were present. Among those who sustained mTBI, severity of PCS at follow-up was associated with history of pre-deployment TBI(s), pre-deployment psychological distress, more severe deployment stress, and loss of consciousness or lapse of memory (versus being "dazed" only) as a result of deployment-acquired mTBI. In summary, we found that sustaining mTBI increases risk for persistent PCS. Previous TBI(s), pre-deployment psychological distress, severe deployment stress, and loss of consciousness or lapse of memory resulting from mTBI(s) are prognostic indicators of persistent PCS after an index mTBI. These observations may have actionable implications for prevention of chronic sequelae of mTBI in the military and other settings.

BACKGROUND: Prior investigations have found negative associations between military unit cohesion and posttraumatic stress disorder (PTSD); however, most relied on cross-sectional data and few examined relationships of unit cohesion to other mental disorders. This study evaluates prospective associations of perceived unit cohesion with a range of mental health outcomes following combat deployment. METHODS: US Army soldiers were surveyed approximately 1–2 months before deployment to Afghanistan (T0); and 1 month (T1), 3 months (T2), and 9 months (T3) after return from deployment. Logistic regression was performed to estimate associations of perceived unit cohesion at T0 with risk of PTSD, major depressive episode (MDE), generalized anxiety disorder (GAD), alcohol or substance use disorder (AUD/SUD), and suicidal ideation at T2 or T3 among soldiers who completed all study assessments (N=4,645). Models adjusted for socio-demographic and Army service characteristics, pre-deployment history of the index outcome, and deployment stress exposure. RESULTS: Higher perceived unit cohesion at T0 was associated with lower risk of PTSD, MDE, GAD, AUD/SUD, and suicidal ideation at T2 or T3 (AORs=0.72 to 0.85 per standard score increase in unit cohesion; ps<.05). Models of incidence of mental disorders and suicidal ideation among soldiers without these problems pre-deployment yielded similar results [AORs=0.65 to 0.79; ps<.01], except that perceived unit cohesion was not associated with incident AUD/SUD. CONCLUSIONS: Soldiers who reported strong unit cohesion before deployment had lower risk of post-deployment mental disorders and suicidal ideation. Awareness of associations of perceived unit cohesion with post-deployment mental health may facilitate targeting of prevention programs.

The Army Study to Assess Risk and Resilience in Servicemembers (Army STARRS) is a multi-component epidemiological and neurobiological study of unprecedented size and complexity designed to generate actionable evidence-based recommendations to reduce U.S. Army suicides and increase basic knowledge about determinants of suicidality by carrying out coordinated component studies. A number of major logistical challenges were faced in implementing these studies. The current report presents an overview of the approaches taken to meet these challenges, with a special focus on the field procedures used to implement the component studies. As detailed in the paper, these challenges were addressed at the onset of the initiative by establishing an Executive Committee, a Data Coordination Center (the Survey Research Center [SRC] at the University of Michigan), and study-specific design and analysis teams that worked with staff on instrumentation and field procedures. SRC staff, in turn, worked with the Office of the Deputy Under Secretary of the Army (ODUSA) and local Army Points of Contact (POCs) to address logistical issues and facilitate data collection. These structures, coupled with careful fieldworker training, supervision, and piloting contributed to the major Army STARRS data collection efforts having higher response rates than previous large-scale studies of comparable military samples.

Insomnia is a worldwide problem with substantial deleterious health effects. Twin studies have shown a heritable basis for various sleep-related traits, including insomnia, but robust genetic risk variants have just recently begun to be identified. We conducted genome-wide association studies (GWAS) of soldiers in the Army Study To Assess Risk and Resilience in Servicemembers (STARRS). GWAS were carried out separately for each ancestral group (EUR, AFR, LAT) using logistic regression for each of the STARRS component studies (including 3,237 cases and 14,414 controls), and then meta-analysis was conducted across studies and ancestral groups. Heritability (SNP-based) for lifetime insomnia disorder was significant (h2g = 0.115, p = 1.78 × 10-4 in EUR). A meta-analysis including three ancestral groups and three study cohorts revealed a genome-wide significant locus on Chr 7 (q11.22) (top SNP rs186736700, OR = 0.607, p = 4.88 × 10-9) and a genome-wide significant gene-based association (p = 7.61 × 10-7) in EUR for RFX3 on Chr 9. Polygenic risk for sleeplessness/insomnia severity in UK Biobank was significantly positively associated with likelihood of insomnia disorder in STARRS. Genetic contributions to insomnia disorder in STARRS were significantly positively correlated with major depressive disorder (rg = 0.44, se = 0.22, p = 0.047) and type 2 diabetes (rg = 0.43, se = 0.20, p = 0.037), and negatively with morningness chronotype (rg = -0.34, se = 0.17, p = 0.039) and subjective well being (rg = -0.59, se = 0.23, p = 0.009) in external datasets. Insomnia associated loci may contribute to the genetic risk underlying a range of health conditions including psychiatric disorders and metabolic disease.

Debate continues about the accuracy of military suicide reporting due to concerns that some suicides may be classified as accidents to minimize stigma and ensure survivor benefits. We systematically reviewed records for 998 active duty Army deaths (510 suicides; 488 accident, homicide and undetermined deaths; 2005-2009) and, using research criteria, reclassified 8.2% of the non-suicide cases to definite suicide (1), suicide probable (4), or suicide possible (35). The reclassification rate to definite suicide was only 0.2% (1/488). This low rate suggests that flagrant misclassification of Army deaths is uncommon and surveillance reports likely reflect the "true" population of Army suicides.

Objectives. To examine associations of administratively recorded sexual assault victimization during military service with subsequent mental health and negative career outcomes among US Army women controlling for nonrandom victimization exposure.