Deployment Health Research Department, Naval Health Research Center, San Diego, CA, USA.
Leidos, Inc, San Diego, CA, USA.
BMC Med Res Methodol. 2023 Sep 9;23(1):205. doi: 10.1186/s12874-023-02018-z.
Patterns of survey response and the characteristics associated with response over time in longitudinal studies are important to discern for the development of tailored retention efforts aimed at minimizing response bias. The Millennium Cohort Study, the largest and longest running cohort study of military personnel and veterans, is designed to examine the long-term health effects of military service and experiences and thus relies on continued participant survey responses over time. Here, we describe the response rates for follow-up survey data collected over 15 years and identify characteristics associated with follow-up survey response and mode of response (paper vs. web).
Patterns of follow-up survey response and response mode (web, paper, none) were examined among eligible participants (n=198,833), who were initially recruited in four panels from 2001 to 2013 in the Millennium Cohort Study, for a follow-up period of 3-15 years (2004-2016). Military and sociodemographic factors (i.e., enrollment panel, sex, birth year, race and ethnicity, educational attainment, marital status, service component, service branch, pay grade, military occupation, length of service, and time deployed), life experiences and health-related factors (i.e., military deployment/combat experience, life stressors, mental health, physical health, and unhealthy behaviors) were used to examine follow-up response and survey mode over time in multivariable generalized estimating equation models.
Overall, an average response rate of 60% was observed across all follow-up waves. Factors associated with follow-up survey response over time included increased educational attainment, married status, female sex, older age, military deployment (regardless of combat experience), and higher number of life stressors, mental health issues, and physical health diagnoses.
Despite the challenges associated with collecting multiple waves of follow-up survey data from members of the U.S. military during and after service, the Millennium Cohort Study has maintained a relatively robust response rate over time. The incorporation of tailored messages and outreach to those groups least likely to respond over time may improve retention and thereby increase the representativeness and generalizability of collected survey data.
在纵向研究中，了解调查响应模式以及随时间变化与响应相关的特征对于制定有针对性的保留措施以尽量减少响应偏差非常重要。千禧年队列研究是对军事人员和退伍军人进行的最大和最长的队列研究，旨在研究兵役和经历对长期健康的影响，因此依赖于随时间推移继续进行参与者调查响应。在这里，我们描述了在 15 年期间收集的后续调查数据的响应率，并确定了与后续调查响应和响应模式（纸质与网络）相关的特征。
在千禧年队列研究中，符合条件的参与者（n=198833 人）最初于 2001 年至 2013 年分四批招募，参加了后续调查，调查期为 3-15 年（2004 年至 2016 年）。军事和社会人口统计学因素（即入伍小组、性别、出生年份、种族和民族、教育程度、婚姻状况、服务部门、服务分支、薪级、军事职业、服役年限和部署时间）、生活经历和与健康相关的因素（即军事部署/战斗经历、生活压力源、心理健康、身体健康和不健康行为）被用于在多变量广义估计方程模型中随时间检查后续响应和调查模式。
总体而言，所有后续波次的平均响应率为 60%。随时间变化与后续调查响应相关的因素包括教育程度提高、已婚状态、女性性别、年龄较大、军事部署（无论是否有战斗经历）以及生活压力源、心理健康问题和身体健康诊断的数量增加。
尽管在服役期间和之后从美国军人中收集多波次后续调查数据存在挑战，但千禧年队列研究随时间保持了相对较高的响应率。针对那些最不可能随时间响应的群体制定有针对性的信息和外展措施可能会提高保留率，从而提高收集调查数据的代表性和通用性。
