Recruiting and retaining service agencies and public health providers in longitudinal studies: Implications for...

This article addresses a lack of attention in the implementation science literature regarding how to overcome recruitment and retention challenges in longitudinal studies involving large samples of service agencies and health service providers ("providers"). Herein, we provide a case-illustration of procedures that improved recruitment and retention in a longitudinal, mixed-method study-Project Interprofessional Collaboration Implementation-funded by the US National Institute of Mental Health. Project Interprofessional Collaboration Implementation included counselors, program workers, educators, and supervisors. We present a research-engagement model to overcome barriers that included developing a low-burden study, social gatherings to engage stakeholders, protocols to recruit agencies and providers, comprehensive record-keeping, research procedures as incentives to participation, a plan to retain hard-to-reach participants, and strategies for modifying incentives over time. Using our model, we retained 36 agencies over the life of the project. Between baseline (N = 379) and 12-month follow-up (N = 285), we retained 75% of the sample and between the 12- (N = 285) and 24-month follow-ups (N = 256), we retained 90%. For qualitative interviews (between baseline and 12-month follow-up and between 12- and 24-month follow-ups), we retained 100% of the sample (N = 20). We provide a summary of frequency of contacts required to initiate data collection and time required for data collection. The model responded to environmental changes in policy and priorities that would not have been achievable without the expertise of community partners. To recruit and retain large samples longitudinally, researchers must strategically engage community partners. The strategies imbedded in our model can be performed with moderate levels of effort and human resources. Creating opportunities for research partners to participate in all phases of the research cycle is recommended, which can help build research capacity for future research.