The Challenges of Locating Young Adults for a Longitudinal Study: Improved Tracing Strategies Implemented for the National Longitudinal Study of Adolescent Health, Wave IV Amanda Meehan, Erica Saleska, Marjorie Hinsdale-Shouse, Nick Kinsey and Casey Tischner AAPOR May 17, 2009 3040 Cornwallis Road P.O. Box 12194 Research Triangle Park, North Carolina, USA 27709 Phone: 919-783-2380 e-mail: ameehan@rti.org RTI International is a trade name of Research Triangle Institute
Maintaining a Longitudinal Sample Maintaining the integrity of the sample for a longitudinal study is key to its success. Studies with long periods between waves make locating sample members challenging. Detailed planning is needed prior to data collection with multiple strategies and approaches to locate sample members successfully. 2
Presentation Overview Identifying the problem Overview of Add Health, Wave IV Methods used Results Summary Future work 3
Identifying the problem Increase locate rate on Add Health Wave IV from previous wave. Locate young adult sample members who had not been contacted since at least 2000-2001. Locate sample members who had not participated since 1994-1995. 4
Overview of Add Health Field study developed as a response to a Congressional mandate to fund a study of adolescent health; designed by Carolina Population Center Funded by the National Institute of Child Health and Human Development (NICHD) in cooperation of 17 other federal agencies. Purpose is to gather longitudinal data on health and health behaviors of young adults and adolescents and their transition into young adulthood. First administered 94-95, with follow-up rounds in 96, 01-02, 08-09 5
Overview of Add Health (cont.) Add Health recently completed fourth wave of data collection. Wave IV involved locating and interviewing sample members who are now ages 24 to 32. The focus of Wave IV involved understanding the connections among social and physical context, risk behavior, and biological processes as they contribute to the health of young adults. 6
Locating Methods Used Batch Tracing More sophisticated vendors used at Wave IV More vendors used in general at Wave IV Respondent Mailings One mailing at Wave IV, after batch tracing completed 7
Locating Methods Used (cont) Interactive Tracing More cases sent to interactive tracing prior to data collection 44% at Wave IV vs. 32% at Wave III More cases located prior to data collection 36% at Wave IV vs. 2.8% at Wave III 8
Locating Methods Used (cont.) Creation of the Interactive Locating System (ILS) Efficiencies in sharing information quickly and securely Additional Batch Tracing Similar approach to Wave III Supplemental Tracing Strategies Some strategies with similarities to Wave III 9
Supplemental Tracing Strategies Social Networking Websites MySpace and Facebook at Wave IV Classmates.com at Wave III Respondent Assisted Tracing (RATS) Much smaller scale than Wave III Detailed Case Review More time devoted to review at Wave IV 10
Results In Wave IV, we located 18,289 sample members for a 92.5% locate rate. Increased the locate rate from Wave III, which was 87%. 11
Wave III and Wave IV Tracing Steps Comparison Tracing Step at which Sample Member Located Wave III Wave IV Advance tracing 37% 66% Interactive tracing (after start of data collection) 26% 10% Located in the field 12% 14% Located via other tracing step 0% 3% Located noninterviews, unknown source 12%* 0% Not Located 13% 8% 12
Wave IV Located Sample Members - Age Comparison Age Group* p<.05 Total Number of Sample Members Percentage Located Percentage Not Located 24-28 years old 9,016 (46%) 95% 5% 29 32+ years old 10,742 (54%) 91% 9% 13
Wave IV Located Sample Members - Last Wave of Participation Comparison Last Wave of Participation* p<.05 Total Number of Sample Members Wave I 1,882 (9%) Wave II 2,909 (15%) Wave III 14,972 (76%) Percentage Located Percentage Not Located 79% 21% 85% 15% 96% 4% 14
Wave IV Located Sample Members Wave III Refusal Status Comparison Wave III Refusal Status* P=.026 Total Number of Sample Members Percentage Located Percentage Not Located Wave III Refusal 1,042 (5%) 91% 9% Wave III Non-refusal 18,721 (95%) 93% 7% 15
Wave IV Located Sample Members SSN Status Comparison SSN Status* p<.05 Total Number of Sample Members Percentage Located Percentage Not Located SSN available for tracing 11,904 (60%) 95% 5% SSN not available for tracing 7,859 (40%) 89% 11% 16
Conclusion Lessons learned from Wave III allowed expansion of tracing techniques. Advance planning and creation of tracing plan helped us carry out our plan to reach 92% locate rate. Improved batch tracing prior to data collection Creation of Interactive Locating System helped standardize tracking and distributing leads which increased efficiency. More resources for case review allowed better management of lead confirmation. Numerous strategies needed to be successful 17
Future Work Continue tracing methods used in Wave IV. Consider use of social networking sites prior to and during data collection. Older and less transient population in future waves 18
Contact Information Amanda Meehan RTI International Phone: 919 783-2380 E-mail: ameehan@rti.org /aapor 19