0704-0635_ssb_4.15.2024

SUPPORTING STATEMENT – PART B

B.  COLLECTIONS OF INFORMATION EMPLOYING STATISTICAL METHODS

If the collection of information employs statistical methods, the following information should be provided in this Supporting Statement:

1.  Description of the Activity

Millennium Cohort Study (MCS) participants with adolescent children between the ages of 11 to 17 were invited to complete a web-based self-report survey (N=38,031) from November 2022 to February 2023. Once the MCS participant logged into the web survey hosted on the study website (www.millenniumcohort.com/soar), they completed consent and HIPAA forms (parent and child), completed the parent survey, and provided contact information for the focal adolescent child identified during the survey. The response rate for the MCS parent was 22% (n=8173). Referred adolescents were invited via email and postal address to complete the SOAR adolescent survey from November 2022 to July 2023. The response rate for invited adolescents was 46% (n=3782).

The SOAR sampling frame for the follow-up survey includes 7,867 adolescents whose parents completed a baseline survey (2022/2023) and provided consent to invite their child, regardless of whether the adolescent completed a baseline survey. We expect an overall response rate of 48%, resulting in an expected sample size of 3,776. Longitudinal follow-up survey data will be collected for at least two additional time points post-baseline. These follow-up assessments will occur at approximately 18-to-24-month intervals, at which time adolescent participants will be about 13-19 years old at Wave 2 and about 15-21 years old at Wave 3. Research findings will shed light on the enduring impact of military life on adolescents and the nature of associations between military-specific experiences and psychosocial health and well-being. Further, this research will assess modifiable risk and protective factors that may elucidate differences in military-connected adolescent psychosocial development and physical health, academic achievement, and educational and military career aspirations over time. Conclusions gleaned from this research will be used to inform existing policy and programs designed to promote adolescent resilience.

2.  Procedures for the Collection of Information

1. Statistical methodologies for stratification and sample selection.

The SOAR sampling frame for the follow-up survey includes 7,867 adolescents whose parents completed a baseline survey (2022/2023) and provided consent to invite their child, regardless of whether the adolescent completed a baseline survey.

2. Estimation procedures;

SOAR plans to adjust for differential attrition at follow-up.

3. Degree of accuracy needed for the Purpose discussed in the justification;

Important subgroups, such as female service members, Reserve/National Guard, Marines, and married service members were originally oversampled to ensure appropriate representation in the Millennium Cohort Study. As such, there is adequate power to detect meaningful effects in these subgroups. In addition, SOAR recruited veteran service members enrolled in MCS to participate if they had adolescent children, which allows us to represent children after they transition from service.

4. Unusual problems requiring specialized sampling procedures; and

N/A

5. Use of periodic or cyclical data collections to reduce respondent burden.

Longitudinal follow-up survey data will be collected for at least two additional time points post-baseline. These follow-up assessments will occur at approximately 18-to-24-month intervals, at which time adolescent participants will be about 13-19 years old at Wave 2 and about 15-21 years old at Wave 3. We expect retention rates for the sample of adolescents to be approximately 48% at each wave of subsequent data collection. Specifically, at wave 2 we expect about 3776 adolescents to participate and at wave 3 we expect about 1,812 adolescents to participate.

3.  Maximization of Response Rates, Non-response, and Reliability

The study will employ several approaches to maximize follow-up response rates and reliability.

• The Millennium Cohort Program has an extensive history in developing marketing materials and using validated techniques to maximize response rates using a modified Dillman method consisting of mailings, emails, postcards, and tokens of appreciation, which will be tailored to adolescent-age participants for the current study.

• We will plan to conduct non-response analyses and analyze patterns of missing data to determine if and where bias may exist.

• In order to maximize follow-up response rates, we will offer incentives to participants in the form of $20 electronic gift cards to Amazon for completing the survey at follow-up and a $30 Amazon electronic gift card for completing a second follow-up survey. Participants will also receive a pre-incentive mailing (less than $5 value) and will be able to download a certificate of participation in the study after completing each survey wave.

• We will send participants personalized emails with study findings as well as emails requesting new contact information; mail personalized holiday postcards and; employ phone calls and personalized text messaging to participants with cell phones if necessary and budget allows.

4.  Tests of Procedures

The measures selected for the adolescent survey largely come from national surveys that have been used for decades to produce valid and reliable data, including the Youth Risk Behavior Survey, the National Survey on Drug Use and Health, and the National Survey of Children’s Health.

5.  Statistical Consultation and Information Analysis

a. Name and telephone number of individual(s) consulted on statistical aspects of the design.

Dr. Hope McMaster, Naval Health Research Center, [email protected], 314-458-5107

Dr. Valerie Stander, Naval Health Research Center, [email protected], 619-553-7174

Dr. Sabrina Richardson, Naval Health Research Center, [email protected], 619-553-7598

Dr. Xin Tu, University of California San Diego, [email protected], 858-822-7485

b. Name and organization of person(s) who will actually collect and analyze the collected information.

Dr. Hope McMaster, Naval Health Research Center

Dr. Valerie Stander, Naval Health Research Center

Dr. Sabrina Richardson, Naval Health Research Center

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