Follow-up Survey Response in Relation to Military Deployments

The longitudinal study of service members is necessary to assess the unique occupational exposures and experiences that may affect long-term health and well-being. However, certain inherent aspects of military service, such as military deployments, may make repeated follow-up survey assessments for collecting ongoing exposures, health symptoms, and health outcomes challenging. The aim of this study was to understand the impact of deployment on follow-up survey response rates across a 3-year period among eligible participants in a large contemporary military cohort.

Data from the Millennium Cohort Study, the largest and longest running study of service members were analyzed to examine the associations between deployment during the paper or web data collection survey cycle on likelihood of response at the first follow-up, approximately 3 years after enrollment for participants originally enrolled between 2001 and 2013.

Bivariate differences suggest those who deployed during the survey cycle were slightly more likely to respond. This modest difference appeared to reverse direction after adjusting for military and demographic characteristics. Among all survey responders, those who deployed during the survey cycle were consistently more likely to complete the web rather than the paper survey than those who did not deploy.

Collecting longitudinal survey data among active duty, Reserve and National Guard service members in deployed settings is feasible.