Beyond Birthday Cards: Maximizing Follow-Up in Longitudinal Studies

In longitudinal randomized control trials, response rates are crucial.  Without high response rates, the level of attrition may impact the outcome data or leave the researcher with a group that is an unrepresentative sample.  To focus on maintaining these response rates, two programs are used as examples.  The Teen Outreach Program is currently being replicated by the Northwest Coalition of Adolescent Health.  In the first two years this program has been delivered at 67 sites with 264 clubs and 4857 students across five states in the Pacific Northwest.  The Children’s Aid Society/Carrera Teen Pregnancy Prevention Program is currently being offered after school in four elementary/middle schools with 338 students in Chicago.  Each of these programs targets high-risk youth.  To maintain high response rates in these evaluations, multiple strategies were used including: in person data collection and follow up; pre-survey day reminders via mail, email, text, and phone; flyers with online links and toll-free numbers distributed by staff, mail, or email; calling for phone surveys; texting information on how to take the survey online or via phone; emailing and calling students when they moved; and having toll-free phone lines for students to survey.  Incentives were also provided for survey completion.  This paper describes each strategy, presenting data on their yields.  Methods were altered over the course of these evaluations as lessons were learned and new challenges were presented.  This led to response rates of over 82% after 24 months in the northwest and 84% after 27 months in Chicago.