User:Millennium cohort/Millennium Cohort Study

The Millennium Cohort Study is a longitudinal cohort study designed to evaluate the long-term health effects of military service, including deployments. It is the largest prospective health project in military history, currently collecting data on over 150,000 enrolled participants.. Investigators that conduct the Millennium Cohort Study include scientists from the Army, Navy, Air Force, Department of Veterans Affairs, and leading academic institutions.



Origin
After the 1991 Gulf War, the Department of Defense recognized the need to collect more information about the long-term health of service members. The Millennium Cohort Study was designed to address that need. Pilot studies were conducted in 2000; by 2001, the Millennium Cohort Study’s first enrollment period was launched, collecting baseline data from over 77,000 people.

Website
The Millennium Cohort Study official website is available at www.millenniumcohort.org

Overview
Funded by the Department of Defense, and supported by military, Department of Veterans Affairs, and civilian researchers, over 150,000 people have already participated.. The Millennium Cohort Study began by enrolling a representative sample of US military personnel, both active duty and Reserve/Guard members. Surveys are sent to participants every three years through email and the USPS, requesting that they submit their data. Although, approximately 20% of Millennium Cohort participants have left military service, the study will continue to follow participants through their active duty, reserve, and civilian endeavors.

Methodology
Participants are requested to submit their surveys via email and USPS invitations, which are mailed in three year cycles. The contact methodology is a modified Dillman method, chosen to optimize response rates from a large cohort via semi-regular contact. The data are collected via the Millennium Cohort website as well as paper surveys. The Millennium Cohort Study has performed multiple reliability assessments, including comparisons of web versus paper responders, and found few significant biases in response mechanism.

In 2001, the study invited its first panel of participants, and named it Panel 1. Panel 1 consists of approximately 77,000 participants. In 2004, the study invited its second panel of participants, and named it Panel 2. Panel 2 numbers approximately 30,000 participants. In 2007, the study invited its third panel of participants, and named it Panel 3. Panel 3 numbers approximately 40,000 participants.

Research
Prospective data analyses are underway to assess health outcomes including PTSD, depression, smoking, and alcohol use that may be associated with deployment in support of the current wars. Currently, more than 40% of Millennium Cohort participants have deployed in support of the wars in Iraq and Afghanistan.

As force health protection continues to be a priority for the future of the United States military, the Millennium Cohort Study will be providing critical information towards enhancing the long-term health of future generations of military members.

Conference Presentations
The investigative team has shared more than 100 presentations at scientific conferences since 2001, and received multiple research awards.

Publications
Below is a chronological list of publications in the medical literature. Many additional products are under development and review.

Smith B, Wong CA, Smith TC, Boyko EJ, Gackstetter GD, Ryan MAK, for the Millennium Cohort Study Team. Newly reported respiratory symptoms and conditions among military personnel deployed to Iraq and Afghanistan: a prospective population-based study. American Journal of Epidemiology, 2009; In press. ''Elevated risk for self-reported respiratory symptoms was found among Army and Marine Corps personnel deployed in support of operations in Iraq and Afghanistan. No increased risk for self-reported asthma, bronchitis, or emphysema was found. Future longitudinal assessment will better explore the relationship between deployment and chronic respiratory conditions.''

Granado NS, Smith TC, Swanson GM, Harris RB, Shahar E, Smith B, Boyko EJ, Wells TS, Ryan MAK, for the Millennium Cohort Study Team. Newly-reported hypertension after military combat deployment in a large population-based study. Hypertension, 2009; In press. Findings suggest that deployers who report multiple combat exposures, especially those who personally witnessed a death due to war or disaster, are at higher risk for newly-reported hypertension, possibly indicating a stress-induced hypertensive effect.

Smith TS, for the Millennium Cohort Study Team. The US Department of Defense Millennium Cohort Study: career span and beyond longitudinal follow-up. Journal of Occupational and Environmental Medicine, 2009; In press. Describes the Millennium Cohort Study, a large longitudinal occupational health study designed and initiated prior to the combat deployments in Iraq and Afghanistan specifically to assess any short or long-term health outcomes during and after military service and career.

Jacobson IG, White MR, Smith TC, Smith B, Wells TS, Gackstetter GD, Boyko EJ, for the Millennium Cohort Study Team. Self-reported health symptoms and conditions among complementary and alternative medicine users in a large military cohort. Annals of Epidemiology, 2009; In press. Findings illustrate that a relatively young adult occupational cohort of military personnel using CAM therapies also report multiple comorbidities which may indicate chronic illness management and poorer overall health.

Wells TS, LeardMann CA, Fortuna SO, Smith B, Smith TC, Ryan MAK, Boyko EJ Blazer D, for the Millennium Cohort Study Team. A prospective study of depression following combat deployment in support of the wars in Iraq and Afghanistan. American Journal of Public Health, 2009; In press. Findings emphasize that exposure to combat, rather than deployment itself, among men and women significantly increase the risk of new-onset depression.

LeardMann CA, Smith TC, Smith B, Wells TS, Ryan MAK, for the Millennium Cohort Study Team. Baseline self-reported functional health predicts vulnerability to posttraumatic stress disorder following combat deployment: prospective US military cohort study. British Medical Journal, 2009 Apr;338:b1273. Military service members who screen in the lowest 15% of health prior to combat exposure are more vulnerable to developing postdeployment PTSD.

Welch KE, LeardMann CA, Jacobson IG, Speigle SJ, Smith B, Smith TC, Ryan MAK, for the Millennium Cohort Study Team. Postcards encourage participant updates. Epidemiology, 2009 Mar;20(2):313-4. The results of this study quantify and confirm that semiannual appreciatory contact is an effective way to maintain communication with a highly mobile participant population while prompting updates of contact information.

Jacobson IG, Smith TC, Smith B, Keel PK, Amoroso PJ, Wells TS, Bathalon GP, Boyko EJ, Ryan MAK for the Millennium Cohort Study Team. Disordered eating and weight changes after deployment: longitudinal assessment of a large US military cohort. American Journal of Epidemiology, 2009 Feb;169(4):415-27. Deployed women who reported combat exposures represent a subgroup at higher risk for developing eating problems and weight loss postdeployment compared with deployed women who did not report combat exposures.

Smith TC, Wingard DL, Ryan MAK, Kritz-Silverstein D, Slymen DJ, Sallis JF, for the Millennium Cohort Study Team. PTSD prevalence, associated exposures, and functional health outcomes in a large, population-based military cohort. Public Health Reports, 2009 Jan;124:90-102. Findings suggest a 2% prevalence of current PTSD symptoms in the US Military that are associated with increased reporting of exposures and decrements in functional health.

Smith B, Ryan MAK, Wingard DL, Patterson TL, Slymen DJ, Macera CA, for the Millennium Cohort Study Team. Cigarette smoking and military deployment: a prospective evaluation. American Journal of Preventive Medicine, 2008 Dec;35(6):539-46. Findings suggest an increase in smoking initiation and recidivism among deployers and highlight the importance of prevention strategies pre, during, and post deployment.

Jacobson IG, Smith TC, Bell NS. Military combat deployment and alcohol use reply. Journal of the American Medical Association. 2008 Dec;300(22):2607. ''Highlights the utility of CAGE screening questions for use as controlling factors for those with potential problems using alcohol at baseline.''

Jacobson IG, Ryan MAK, Hooper TI, Smith TC, Amoroso PJ, Boyko EJ, Gackstetter GD, Wells TS, Bell NS, for the Millennium Cohort Study Team. Alcohol use and alcohol-related problems before and after military combat deployment. Journal of the American Medical Association, 2008 Aug;300(6):663-75. Findings suggest that Reserve and National Guard personnel and younger service members who deploy with reported combat exposures are at increased risk of new-onset heavy weekly drinking, binge drinking, and other alcohol-related problems.

Smith B, Chu LK, Smith TC, Amoroso PJ, Boyko EJ, Hooper TI, Gackstetter GD, Ryan MAK, for the Millennium Cohort Study Team. Challenges of self-reported medical conditions and electronic medical records among members of a large military cohort. BMC Medical Research Methodology, 2008 June, 8:37. This report highlights the importance of assessing medical conditions from multiple electronic and self-reported sources.

Smith TC, Wingard DL, Ryan MAK, Kritz-Silverstein D, Slymen DJ, Sallis JF, for the Millennium Cohort Study Team. Prior assault and posttraumatic stress disorder after combat deployment. Epidemiology, 2008 May;19(3):505-12. In contrast to hypotheses that survival from trauma represents or confers resilience, these findings suggest vulnerability to combat stress and PTSD among survivors of prior assault.

Wells TS, LeardMann CA, Smith TC, Smith B, Jacobson IG, Reed RJ, Ryan MAK, for the Millennium Cohort Study Team. Self-reported adverse health events following smallpox vaccination in a large prospective study of US military service members. Human Vaccines. 2008 Mar/Apr;4(2):127-33. ''Smallpox vaccination was not associated with any adverse self-reported health outcomes, including mental and physical functioning. These findings may be reassuring to health care providers and those who receive the smallpox vaccination.''

Wells TS, Jacobson IG, Smith TC, Spooner CN, Smith B, Reed RJ, Amoroso PJ, Ryan MAK, for the Millennium Cohort Study Team. Prior health care utilization as a determinant to enrollment in a 22-year prospective study, the Millennium Cohort Study. European Journal Of Epidemiology. 2008 Feb;23(2):79-87. Few health differences between Millennium Cohort responders and non-responders were found when comparing healthcare utilization in the 12 months preceding study invitation.

Smith TC, Ryan MAK, Wingard DL, Slymen DJ, Sallis JF, Kritz-Silverstein D, for the Millennium Cohort Study Team. New onset and persistent symptoms of posttraumatic stress disorder self-reported after deployment and combat exposures: prospective population-based US military cohort study. British Medical Journal. 2008 Feb;336(7640):366-71. Findings define the importance of PTSD in this population and emphasize that specific combat exposures, rather than deployment itself, significantly affect the onset of PTSD symptoms postdeployment.

Smith B, Wingard DL, Ryan MAK, Macera CA, Patterson TL, Slymen DJ, for the Millennium Cohort Study Team. US military deployment during 2001-2006: comparison of subjective and objective data sources in a large prospective health study. Annals of Epidemiology. 2007 Dec;17(12):976-82. ''Defining military deployments using multiple data sources is examined. Deployment timing and duration metrics, critical for epidemiological studies, are valid in the Millennium Cohort Study.''

Smith TC, Zamorski M, Smith B, Riddle JR, LeardMann CA, Wells TS, Engel CC, Hoge CW, Adkins J, Blazer D, for the Millennium Cohort Study Team. The physical and mental health of a large military cohort: baseline functional health status of the Millennium Cohort. BMC Public Health. 2007 Nov;7:340. The functional health of service members in this 22-year longitudinal study compares favorably at baseline with other civilian and military populations.

LeardMann CA, Smith B, Smith TC, Wells TS, Ryan MAK, for the Millennium Cohort Study Team. Smallpox vaccination: comparison of self-reported and electronic vaccine records in the Millennium Cohort Study. Human Vaccines. 2007 Nov/Dec;3(6):245-51. ''Self-report of smallpox vaccination is very reliable. Results may be valuable in supporting global response to bioterrorism threats.''

Smith B, Smith TC, Gray GC, Ryan MAK, for the Millennium Cohort Study Team. When epidemiology meets the Internet: Web-based surveys in the Millennium Cohort Study. American Journal of Epidemiology. 2007 Nov;166(11):1345-54. Optimal use of the Internet - with minimal response bias, maximum cost-savings, and improved data - is highlighted.

Smith TC, Jacobson IG, Smith B, Hooper TI, Ryan MAK, for the Millennium Cohort Study Team. The occupational role of women in military service: validation of occupation and prevalence of exposures in the Millennium Cohort Study. International Journal of Environmental Health Research. 2007 Aug;17(4):271-84. ''Data on women's occupations are reliable, and occupational codes can be well correlated with exposures of concern. This was an award-winning presentation at a Navy conference in 2006. ''

Smith TC, Smith B, Jacobson IG, Corbeil TE, Ryan MAK, for the Millennium Cohort Study Team. Reliability of standard health assessment instruments in a large, population-based cohort study. Annals of Epidemiology. 2007 Jul;17(7):525-32. Reliability metrics, by test-retest concordance and internal consistency, are extremely strong in Millennium Cohort Study data.

Smith B, Leard CA, Smith TC, Reed RJ, Ryan MAK, for the Millennium Cohort Study Team. Anthrax vaccination in the Millennium Cohort: validation and measures of health. American Journal of Preventive Medicine. 2007 Apr;32(4):347-53. ''The largest ever evaluation of this topic revealed strong validity of self-reported vaccination, as well as unique health features of the small subset who may misreport vaccination. This work won awards at two research conferences in 2006.''

Ryan MA, Smith TC, Smith B, Amoroso P, Boyko EJ, Gray GC, Gackstetter GD, Riddle JR, Wells TS, Gumbs G, Corbeil TE, Hooper TI, for the Millennium Cohort Study Team. Millennium Cohort: enrollment begins a 21-year contribution to understanding the impact of military service. Journal of Clinical Epidemiology. 2007 Feb; 60(2):181-91. ''A foundation report, this describes original enrollment methods and challenges of the Millennium Cohort Study. Characteristics of the first 77,047 participants are detailed and shown to strongly represent the population-based sample of the U.S. military from which they were drawn.''

Riddle JR, Smith TC, Smith B, Corbeil TE, Engel CC, Wells TS, Hoge CW, Adkins J, Zamorski M, Blazer D, for the Millennium Cohort Study Team. Millennium Cohort: the 2001-2003 baseline prevalence of mental disorders in the US military. Journal of Clinical Epidemiology. 2007 Feb; 60(2):192-201. The baseline prevalence of mental disorders in this 21-year longitudinal study compares favorably with other civilian and military populations.

Chretien JP, Chu LK, Smith TC, Smith B, Ryan MAK, for the Millennium Cohort Study Team. Demographic and occupational predictors of early response to a mailed invitation to enroll in a longitudinal health study. Biomed Central Medical Research Methodology. 2007 Jan; 7:6. ''Those who respond first to study invitations, whether to participate or decline, have distinct characteristics within the study population. This information can help structure recruitment efforts.''

Smith TC, Smith B, Corbeil TE, Ryan MAK, Riddle JR, for the Millennium Cohort Study Team. Impact of terrorism on caffeine and tobacco use [letter in response to &quot;Self-reported mental health among US military personnel, prior and subsequent to the terrorist attacks of September 11, 2001&quot;]. Journal of Occupational and Environmental Medicine. 2004 Dec; 46(12):1194-5. Authors of a previously highlighted article respond to important suggestions on future analyses.

Smith TC, Smith B, Corbeil TE, Riddle JR, and Ryan MAK, for the Millennium Cohort Study Team. Self-reported mental health among US military personnel, prior and subsequent to the terrorist attacks of September 11, 2001. Journal of Occupational and Environmental Medicine. 2004 Aug; 46(8):775-82. ''Accepted without revision and featured by journal editors, this early analysis leveraged Millennium Cohort data to conclude that military members displayed stronger mental health characteristics soon after the terrorist attacks of September 11, 2001. The authors suggest this may be attributed to resilience and/or an outpouring of support for the US military mission.''

Gray GC, Chesbrough KB, Ryan MAK, Amoroso P, Boyko EJ, Gackstetter GD, Hooper TI, Riddle JR, for the Millennium Cohort Study Group. The Millennium Cohort Study: A 21-year prospective cohort study of 140,000 military personnel. Military Medicine. 2002 Jun; 167(6):483-8. ''The origins and development of the Millennium Cohort Study are described. The largest prospective study in military history was established to answer the most difficult questions about long-term health after military service.''