Tracking Assault-injured, Drug-using Youth in Longitudinal Research: Follow-up Methods

Violence is one of the leading causes of death among youth ages 14 to 24. Hospital- and emergency department (ED)-based violence prevention programs are increasingly becoming a critical part of public health efforts; however, evaluation of prevention efforts is needed to create evidence-based best practices. Retention of study participants is key to evaluations, although little literature exists regarding optimizing follow-up methods for violently injured youth. This study aims to describe the methods for retention in youth violence studies and the characteristics of hard-to-reach participants.

The Flint Youth Injury (FYI) Study is a prospective study following a cohort of assault-injured, drug-using youth recruited in an urban ED, and a comparison population of drug-using youth seeking medical or non-violence-related injury care. Validated survey instruments were administered at baseline and four follow-up time points (6, 12, 18, and 24 months). Follow-up contacts used a variety of strategies and all attempts were coded by type and level of success. Regression analysis was used to predict contact difficulty and follow-up interview completion at 24 months.

A total of 599 patients (ages 14-24) were recruited from the ED (mean ± SD age = 20.1 ± 2.4 years, 41.2% female, 58.2% African American), with follow-up rates at 6, 12, 18, and 24 months of 85.3%, 83.7% 84.2%, and 85.3%, respectively. Participant contact efforts ranged from two to 53 times per follow-up time frame to complete a follow-up appointment, and more than 20% of appointments were completed off site at community locations (e.g., participants' homes, jail/prison). Participants who were younger (p < 0.05) and female (p < 0.01) were more likely to complete their 24-month follow-up interview. Participants who sought care in the ED for assault injury (p < 0.05) and had a substance use disorder (p < 0.01) at baseline required fewer contact attempts to complete their 24-month follow-up, while participants reporting a fight within the immediate 3 months before their 24-month follow-up (p < 0.01) required more intensive contact efforts.

The FYI study demonstrated that achieving high follow-up rates for a difficult-to-track, violently-injured ED population is feasible through the use of established contact strategies and a variety of interview locations. Results have implications for follow-up strategies planned as part of other violence prevention studies.