Engaging military couples in marital research: does requesting referrals from service members to recruit their spouses introduce sample bias?

Abstract

BackgroundWhile enrolling dyads in research studies is not uncommon, there is limited literature on the utility of different recruitment strategies and the resulting selection biases. This paper examined two recruitment strategies used to enroll military couples in a longitudinal study, assessing the impact of both strategies on the representativeness of the final study sample.MethodDescriptive and bivariate analyses were conducted to 1) identify characteristics associated with spouse referral, 2) compare response rates based on recruitment strategy and assess whether recruitment strategy modified correlates of response propensity among spouses, and 3) assess whether referred spouse characteristics differed from non-referred spouses in the final sample. The study sample consisted of married US service members with 2–5 years of military service as of October 2011 and their spouses.ResultsService members who referred their spouses to participate in the Millennium Cohort Family Study were more likely to be male, have children, serve in the Army, and have combat deployment experience than those who did not refer their spouse. Nearly two-thirds (n = 5331, 64.9%) of referred spouses participated in the Family Study, compared with less than one-third (n = 3458, 29.5%) of directly contacted spouses. Spouse characteristics also differed significantly between recruitment groups.ConclusionsOverall results suggest that minimal bias was introduced by using a referral recruitment methodology. Service members appeared to be more likely to refer their spouses if they perceived the research topic as relevant to their spouse, such that male service members with combat deployment experience were more likely to refer female spouses caring for multiple children. Referred spouses were significantly more likely to respond to the Millennium Cohort Family Study survey than those who were directly contacted; however, the overall success rate of using a referral strategy was less than recruiting spouses through direct contact. Differences between referred spouses and spouses contacted directly mirrored service member referring characteristics.

Prevalence of psychiatric morbidity in United States military spouses: The Millennium Cohort Family Study

“…The Family Study comprises dyadic data from spouses who completed the Family Study questionnaire, as well as service members who participated in the Millennium Cohort. Additional details regarding Family Study recruitment, enrollment, and nonresponse are provided elsewhere (Corry, Williams, Battaglia, McMaster, & Stander, ; McMaster et al. ; McMaster, LeardMann, Speigle, & Dillman, , manuscript in preparation).…”

Influence of Work and Life Stressors on Marital Quality among Dual and Nondual Military Couples

“…Spouses married to these newly enrolled participants ( N = 28,603) were then invited to join the Millennium Cohort Family Study (Family Study), resulting in 9,872 dyads who enrolled and completed baseline surveys within the same study recruitment period. Further explanation of the methodology of the Family Study has been described elsewhere in detail (Corry et al, 2017; McMaster et al, 2017, 2018). This study was approved by an institutional review board, and the research was conducted in agreement with all applicable federal regulations governing the protection of human subjects in research.…”

“…Exposure to potentially challenging military stress experiences in the last 12 months was assessed based on the spouse’s self-report of whether they encountered key military events related to the service member’s deployment, injury, training schedule, or moving (McMaster et al, 2018). Deployment and injury domains were captured using three items each (e.g., deployment: “A combat-related deployment or duty assignment”; injury: “Caring for your ill, injured, or disabled spouse”), while intensified training schedule and permanent change of station (PCS) experiences were measured using single items.…”

“…There are currently over 200,000 participants enrolled in the study representing all branches of the service including the Reserve and National Guard who are surveyed approximately every 3 years and will be followed at least through 2068. Beginning in 2011, the spouses of personnel newly enrolling in Millennium Cohort were enrolled in the Millennium Cohort Family Study (Family Study) (Corry et al, 2017; McMaster et al, 2017, 2018). The Family Study is currently the only ongoing longitudinal population-based cohort of military spouses and was designed to further understand the impact of military life on the health and well-being of the entire military family, including the service member, spouse, and children.…”

Posttraumatic Stress Disorder Symptom Clusters in Service Members Predict New‐Onset Depression Among Military Spouses

“…After giving informed consent, both individuals in the dyad completed separate surveys at baseline (i.e., 2011–2013) and then again approximately 3–5 years later (i.e., 2014–2016). Herein, the partner who completed the Millennium Cohort Study is referred to as the “service member,” and the spouse who completed the Family Study survey is referred to as the “spouse participant.” The methodologies of the Family and Millennium Cohort Study are described in‐depth elsewhere (Corry et al., 2017; McMaster et al., 2017, 2018; Ryan et al., 2007). All study procedures were reviewed and approved by the institutional review board at the Naval Health Research Center.…”