Headache disorders in the millennium cohort: epidemiology and relations with combat deployment.

OBJECTIVE: Characterize migraine and other headache disorders within a large population-based US military cohort, with an emphasis on the temporal association between military deployment and exposure to combat. BACKGROUND: Little research has been published on the prevalence of headache disorders in the US military population, especially in relation to overseas deployments and exposure to combat. A higher than expected prevalence of migraine has previously been reported among deployed US soldiers in Iraq, suggesting an association. Headache disorders, including migraine, could have important effects on the performance of service members. METHODS: A total of 77,047 US active-duty, Reserve, and National Guard members completed a baseline questionnaire between July 2001 to June 2003 for the Millennium Cohort Study. Headache disorders were assessed using the following survey-based measures: self-reported history of provider-diagnosed migraine, recurrent severe headache within the past year, and recent headaches/bothered a lot within the past 4 weeks. Follow-up surveys were completed on average 3 years after baseline (mean=2.7 years; range=11.4 months to 4.5 years). RESULTS: The overall male and female prevalence of self-reported headache conditions at baseline were: provider-diagnosed migraine, 6.9% and 20.9%, respectively; recurrent severe headache, 9.4% and 22.3%, respectively; and bothered a lot by headaches, 3.4% and 10.4%, respectively. Combat deployers had significantly higher odds of any new-onset headache disorders than non-deployers (adjusted odds ratios=1.72 for men, 1.84 for women; 95% confidence intervals, 1.55-1.90 for men, 1.55-2.18 for women), while deployers without combat exposure did not. CONCLUSIONS: Deployed personnel with reported combat exposure appear to represent a higher risk group for new-onset headache disorders. The identification of populations at higher risk of development of headache provides support for targeted interventions.

Longitudinal Assessment of Self-Reported Recent Back Pain and Combat Deployment in the Millennium Cohort Study.

STUDY DESIGN: A prospective cohort study. OBJECTIVE: Activities performed during military operations vary in complexity and physical demand. The risk for mental illness following military combat deployment has been well documented. However, information regarding the possible contribution of back pain to decreased mental and functional health is scarce. To our knowledge, this is the first study to prospectively assess deployment and self-reported recent back pain in a population-based U.S. military cohort. SUMMARY OF BACKGROUND DATA: The study consisted of Millennium Cohort participants who were followed for the development of back pain for an average of 3.9 years. METHODS: Descriptive statistics and longitudinal analyses were used to assess the temporal relationship of deployment with self-reported recent back pain at follow-up (N = 53,933). RESULTS: Recent back pain was self-reported by 8379 (15.5%) participants at follow-up. After adjusting for covariates, deployers with combat experiences had higher odds [odds ratio (OR) = 1.38, 95% confidence interval (95% CI): 1.28-1.50] of recent back pain than noncombat deployers. There was no association between recent back pain and nondeployers compared with noncombat deployers. Service support/supply handlers were at an increased odds of reporting recent back pain (OR = 1.11, 95% CI: 1.02-1.21) than functional support/administration occupations. Occupations associated with a physically demanding work environment had a higher risk of back pain. CONCLUSION: Deployers with combat experiences were more likely to report back pain postdeployment. This well-defined group of military personnel may potentially benefit from integrated prevention efforts. LEVEL OF EVIDENCE: 3.

The association of predeployment and deployment-related factors on dimensions of postdeployment wellness in U.S. military service members.

PURPOSE: To assess the effects of predeployment and deployment-related factors on dimensions of wellness following deployment. DESIGN: Prospective longitudinal study. The dependent variable was dimensions of wellness. Independent variables were measured in terms of modifiable, nonmodifiable, and military factors, such as sex, race/ethnicity, service branch, smoking status, and combat experience. SETTING: A large military cohort participating in the Millennium Cohort Study. SUBJECTS: Included 10,228 participants who deployed in support of the operations in Iraq and Afghanistan. MEASURES: Dimensions of wellness were measured by using standardized instruments assessing self-reported physical health, mental health, and stress. Covariates were measured by using self-reported and electronic data. ANALYSIS: Factors of postdeployment wellness were assessed by using ordinal logistic regression. RESULTS: Most participants (78.7%) were categorized as "moderately well" post deployment. Significant modifiable predeployment predictors of postdeployment wellness included normal/underweight body mass index (odds ratio [OR] = 1.72, p < .05). Military factors significantly associated with wellness included not experiencing combat (OR = .56, p < .05), member of Air Force (OR = 2.02, p < .05) or Navy/Coast Guard (OR = 1.47, p < .05), and combat specialist occupation (OR = 1.22, p < .05). CONCLUSION: Multiple modifiable factors associated with postdeployment wellness were identified, which may help inform medical and military leadership on potential strategies to ensure a well force. Those trained in combat roles were more likely to be well post deployment though this apparent benefit was not conferred onto those reporting combat experiences.

Newly reported lupus and rheumatoid arthritis in relation to deployment within proximity to a documented open-air burn pit in Iraq.

OBJECTIVE: To assess the relationship between possible exposure to smoke from documented open-air burn pits and newly reported lupus and rheumatoid arthritis among Millennium Cohort participants who have deployed in support of operations in Iraq and Afghanistan. METHODS: Prospectively assessed self-reported lupus and rheumatoid arthritis among deployers who completed both 2004-2006 and 2007-2008 questionnaires. RESULTS: After exclusions, more than 18,000 participants were deployed, including more than 3000 participants deployed within a 3-mile radius of a documented burn pit. After adjustment, proximity within 3 miles of a burn pit was not significantly associated with rheumatoid arthritis or lupus in general; however, one location was associated with lupus, although few cases were at this site (n = 2). CONCLUSIONS: Results indicate deployers potentially exposed to documented burn pits in the combined three-camp analysis were not at an elevated risk of lupus or rheumatoid arthritis.

Individual augmentee deployment and newly reported mental health morbidity.

OBJECTIVE: To investigate the association between US Navy individual augmentee (IA) deployers, who may lack the protective effects of unit cohesion and social support, and newly reported mental health. METHODS: Responses from the Millennium Cohort Study questionnaires were examined for 2086 Navy deployers in this prospective exploratory study. Multivariable logistic regression was used to evaluate IA deployment and newly reported mental health symptoms. RESULTS: After adjusting for covariates, IA deployment was not significantly associated with newly reported posttraumatic stress disorder (odds ratio = 1.02; 95% confidence interval: 0.53-1.95) or mental health symptoms (odds ratio = 1.03; 95% confidence interval: 0.66-1.60) compared with non-IA deployment. CONCLUSION: IA deployment was not associated with increased risk for posttraumatic stress disorder or mental health symptoms following deployment. It is likely that social isolation was not highly influential among Navy IAs in this study.

A prospective study of lupus and rheumatoid arthritis in relation to deployment in support of iraq and afghanistan: the millennium cohort study.

The objective of this study was to prospectively assess the association between deployment in support of the operations in Iraq and Afghanistan and newly reported lupus and rheumatoid arthritis while also considering the effects of demographic, behavioral, and occupational characteristics. A total of 77,047 (2001-2003) and 31,110 (2004-2006) participants completed the baseline Millennium Cohort questionnaire and were resurveyed approximately every 3 years. Longitudinal analyses were used to assess the adjusted association between deployment to Iraq and Afghanistan with and without combat exposures and newly reported disease. After adjusting, deployment was not significantly associated with newly reported lupus compared with nondeployers. However, compared with nondeployers, deployers with and without combat exposures were significantly less likely to newly report rheumatoid arthritis. Women, non-Hispanic black, and Hispanic participants had a significantly elevated risk for both diseases. Overall, deployment was not associated with an increased risk of newly reported lupus or rheumatoid arthritis.

Newly reported hypertension after military combat deployment in a large population-based study.

High-stress situations, such as combat deployments, are a potential risk factor for hypertension. Although stress is postulated to increase blood pressure, the underlying role of stress on hypertension is not well established. We sought to determine the relations between combat deployment-induced stress and hypertension. The Millennium Cohort baseline questionnaire (2001-2003) was completed by 77,047 US active-duty and Reserve/National Guard members. Follow-up was completed by 55,021 responders approximately 3 years later (2004-2006). Multivariable logistic regression was used to estimate the 3-year risk of newly reported hypertension, adjusting for general and mental health, demographics, and occupational and behavioral characteristics. After applying exclusion criteria, our analyses included 36 061 service members. Subanalyses of deployers included 8829 participants. Newly reported hypertension was identified in 6.9% of the cohort between baseline and follow-up, many of whom had deployed on military operations in support of the conflicts in Iraq and Afghanistan. After adjusting, deployers who experienced no combat exposures were less likely to report hypertension than nondeployers (odds ratio: 0.77; 95% CI: 0.67 to 0.89). Among deployers, those reporting multiple combat exposures were 1.33 times more likely to report hypertension compared with noncombat deployers (95% CI: 1.07 to 1.65). Although military deployers, in general, had a lower incidence of hypertension than nondeployers, deployment with multiple stressful combat exposures appeared to be a unique risk factor for newly reported hypertension.