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

BACKGROUND: While 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. METHOD: Descriptive 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. RESULTS: Service 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. CONCLUSIONS: Overall 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.

Depression among military spouses: Demographic, military, and service member psychological health risk factors.

BACKGROUND: More than a decade of war has strained service members and their families and the psychological health of military spouses is a concern. This study uses data from the largest study of military families in the United States to examine the demographic, military-specific, and service member mental health correlates of probable diagnosis of major depressive disorder (MDD) among military spouses. METHODS: Data were from service member-spouse dyads from all branches of the U.S. military. Demographic and military-specific factors were assessed using administrative personnel records and survey data. RESULTS: Of the 9,038 spouses, 4.9% had a probable diagnosis of MDD. In unadjusted models, spouses of service members who deployed and experiencecd combat-related events, were enlisted, had a probable posttraumatic stress disorder (PTSD) diagnosis, or screened positive for alcohol misuse were more likely to screen positive for MDD. In adjusted models, only spouses married to enlisted service members or those with PTSD had increased risk for MDD. Other demographic and military-related factors associated with MDD in spouses included less educational attainment, unemployment, having four or more children, and having prior military service (although not currently serving in the military) in the adjusted models. CONCLUSIONS: Findings characterize demographic, military, and service member psychological health factors that are associated with depression among military spouses. These findings imply that deployment alone may not negatively affect military spouses, but rather it may be the mental health impact on the service member, especially PTSD that increases the odds for MDD among military spouses.