All authors declare that they have no competing interests.
JH had full access to all of the data in the study and takes responsibility for the integrity of the data and the accuracy of the data analysis. All authors were involved in the study concept and design. JH and IJ worked on the data analysis and all authors were involved in the analysis plans and interpretation of data and results. All authors contributed to the writing of the manuscript and critically reviewed for important intellectual content. All authors reviewed and approved the final version to be published.
Longitudinal cohort studies are highly valued in epidemiologic research for their ability to establish exposure-disease associations through known temporal sequences. A major challenge in cohort studies is recruiting individuals representative of the targeted sample population to ensure the generalizability of the study’s findings.
We evaluated nearly 350,000 invited subjects (from 2004-2008) of the Millennium Cohort Study, a prospective cohort study of the health of US military personnel, for factors prior to invitation associated with study enrollment. Multivariable logistic regression was utilized, adjusting for demographic and other confounders, to determine the associations between both deployment experience and prior healthcare utilization with enrollment into the study.
Study enrollment was significantly greater among those who deployed prior to and/or during the enrollment cycles or had at least one outpatient visit in the 12 months prior to invitation. Mental disorders and hospitalization for more than two days within the past year were associated with reduced odds of enrollment.
These findings suggest differential enrollment by deployment experience and health status, and may help guide recruitment efforts in future studies.
Sever LE: Epidemiologic approaches to the study of diseases of complex etiology. Birth Defects Orig Artic Ser. 1984, 20 (6): 96-119. PubMed
Young AF, Powers JR, Bell SL: Attrition in longitudinal studies: who do you lose?. Aust Nz J Publ Heal. 2006, 30 (4): 353-361. 10.1111/j.1467-842X.2006.tb00849.x. CrossRef
Littman AJ, Boyko EJ, Jacobson IG, Horton J, Gackstetter GD, Smith B, Hooper T, Wells TS, Amoroso PJ, Smith TC, et al: Assessing nonresponse bias at follow-up in a large prospective cohort of relatively young and mobile military service members. BMC Med Res Methodol. 2010, 10: 99-10.1186/1471-2288-10-99. CrossRefPubMedPubMedCentral
Little R, Rubin DB: Statistical analysis with missing data. 2002, New York: Wiley, 2
Greenland S: Response and follow-up bias in cohort studies. Am J Epidemiol. 1977, 106 (3): 184-187. PubMed
Kleinbaum DG, Morgenstern H, Kupper LL: Selection bias in epidemiologic studies. Am J Epidemiol. 1981, 113 (4): 452-463. PubMed
Lohr SL: Brooks/Cole CENGAGE Learning. Sampling: design and analysis. 2009, Second edn
Hoge CW, Messer SC, Castro CA: Combat duty in Iraq and Afghanistan and mental health problems - reply. New Engl J Med. 2004, 351 (17): 1799-1800.
Hoge CW, Auchterlonie JL, Milliken CS: Mental health problems, use of mental health services, and attrition from military service after returning from deployment to Iraq or Afghanistan. Jama-J Am Med Assoc. 2006, 295 (9): 1023-1032. 10.1001/jama.295.9.1023. CrossRef
Gray GC, Kaiser KS, Hawksworth AW, Hall FW, Barrett-Connor E: Increased postwar symptoms and psychological morbidity among US Navy Gulf War veterans. AmJTrop Med Hyg. 1999, 60 (5): 758-766.
Smith TC, Ryan MAK, Wingard DL, Slymen DJ, Sallis JF, Kritz-Silverstein D, Team MCS: New onset and persistent symptoms of post-traumatic stress disorder self reported after deployment and combat exposures: prospective population based US military cohort study. Brit Med J. 2008, 336 (7640): 366-371. 10.1136/bmj.39430.638241.AE. CrossRefPubMedPubMedCentral
Wells TS, LeardMann CA, Fortuna SO, Smith B, Smith TC, Ryan MAK, Boyko EJ, Blazer D, Team MCS: A prospective study of depression following combat deployment in support of the wars in Iraq and Afghanistan. Am J Public Health. 2010, 100 (1): 90-99. 10.2105/AJPH.2008.155432. CrossRefPubMedPubMedCentral
Wells TS, Jacobson IG, Smith TC, Spooner CN, Smith B, Reed RJ, Amoroso PJ, Ryan MAK, Team MCS: Prior health care utilization as a potential determinant of enrollment in a 21-year prospective study, the millennium cohort study. Eur J Epidemiol. 2008, 23 (2): 79-87. 10.1007/s10654-007-9216-0. CrossRefPubMed
Gray GC, Chesbrough KB, Ryan MA, Amoroso P, Boyko EJ, Gackstetter GD, Hooper TI, Riddle JR: The millennium cohort study: a 21-year prospective cohort study of 140,000 military personnel. Mil Med. 2002, 167 (6): 483-488. PubMed
Ryan MA, Smith TC, Smith B, Amoroso P, Boyko EJ, Gray GC, Gackstetter GD, Riddle JR, Wells TS, Gumbs G, et al: Millennium cohort: enrollment begins a 21-year contribution to understanding the impact of military service. J Clin Epidemiol. 2007, 60 (2): 181-191. 10.1016/j.jclinepi.2006.05.009. CrossRefPubMed
Dillman DA, Phelps G, Tortora R, Swift K, Kohrell J, Berck J, Messer BL: Response rate and measurement differences in mixed-mode surveys using mail, telephone, interactive voice response (IVR) and the Internet. Soc Sci Res. 2009, 38 (1): 3-20. CrossRef
Dillman DA, Lesser V, Mason R, Carlson J, Willits F, Robertson R, Burke B: Personalization of mail surveys for general public and populations with a group identity: results from nine studies. Rural Sociol. 2007, 72 (4): 632-646. 10.1526/003601107782638693. CrossRef
Dillman DA: Mail and internet surveys: the tailored design method. 2000, New York: Wiley
Glantz S, Slinker B: Primer of applied Regression and analysis of variance. 1990, New York, NY: McGraw-Hill
Heberlein TA, Baumgartner R: Factors affecting response rates to mailed questionnaires - quantitative-analysis of published literature. Am Sociol Rev. 1978, 43 (4): 447-462. 10.2307/2094771. CrossRef
Spitzer RL, Kroenke K, Linzer M, Hahn SR, Williams JBW, Degruy FV, Brody D, Davies M: Health-related quality-of-life in primary-care patients with mental-disorders - results from the prime-md 1000 study. Jama-J Am Med Assoc. 1995, 274 (19): 1511-1517. 10.1001/jama.1995.03530190025030. CrossRef
Wells KB, Stewart A, Hays RD, Burnam MA, Rogers W, Daniels M, Berry S, Greenfield S, Ware J: The functioning and well-being of depressed-patients - results from the medical outcomes study. Jama-J Am Med Assoc. 1989, 262 (7): 914-919. 10.1001/jama.1989.03430070062031. CrossRef
Lundberg I, Thakker KD, Hallstrom T, Forsell Y: Determinants of non-participation, and the effects of non-participation on potential cause-effect relationships, in the part study on mental disorders. Soc Psych Psych Epid. 2005, 40 (6): 475-483. 10.1007/s00127-005-0911-4. CrossRef
- The impact of deployment experience and prior healthcare utilization on enrollment in a large military cohort study
Jaime L Horton
Isabel G Jacobson
Alyson J Littman
John E Alcaraz
Nancy F Crum-Cianflone
- BioMed Central
Neu im Fachgebiet AINS
Meistgelesene Bücher aus dem Fachgebiet AINS
Mail Icon II