Locating longitudinal study participants 10 years after last contact: Contemporary approaches to sample retention.

AIMS: Despite their advantages, longitudinal studies often face high rates of attrition. This study documents the extensive efforts associated with retaining a longitudinal cohort last contacted 10 years earlier. METHOD: We examine the processes and outcomes of attempts to reach 1736 individuals who have been part of a multiwave study about growing up in Ontario, Canada. Contact methods include email, phone, text, social media, postal mail, announcements in newspapers, subway stations, and music streaming services. RESULTS: Challenges included a lack of consistent annual communication with participants, children moving out of the parental home, and changes in email addresses and phone numbers. The most effective contact method was phone; text messages and friend referrals were the least effective. Overall, 41.5% of the original sample was reached. Locating former research participants years later necessitated multiple and repeated contact attempts, and intensive human resources. CONCLUSION: Ten lessons for effective sample retention are discussed. In summary, reducing attrition depends on a comprehensive study design and an organized and flexible protocol that adapts to a study's ever-changing needs.

Waterloo Better Beginnings as a Transformative Prevention Project: Impacts on Children, Parents, and the Community.

Better Beginnings Waterloo (BBW) is an ecological, community-driven, prevention program for children aged 4-8 and their families. BBW was implemented in two low-income communities with high percentages of visible minorities. Data on Grade 1-2 children and their parents (the baseline comparison group) were gathered through parent interviews (n = 34) and teacher reports (n = 68) in 2015, prior to BBW programs, and in the period 2018-2019, the same data were collected through parent interviews (n = 47) and teacher reports (n = 46) for children and parents participating in programs (the BBW group). As well, qualitative, open-ended individual interviews with parents (n = 47) and two focus groups were conducted in the period 2018-2019. Children in the BBW cohort were rated by their teachers as having a significantly lower level of emotional and behavioural problems than those in the baseline sample; parents in the BBW cohort had significantly higher levels of social support than parents in the baseline cohort; BBW parents rated their communities significantly more positively than parents at baseline. The qualitative data confirmed these findings. The quantitative and qualitative short-term findings from the BBW research showed similar positive impacts to previous research on program effectiveness, thus demonstrating that the Better Beginnings model can be successfully transferred to new communities.