Retention in a 6-Month Smoking Cessation Study Among Alaska Native and American Indian People.

Participant retention in longitudinal health research is necessary for generalizable results. Understanding factors that correlate with increased retention could improve retention in future studies. Here, we describe how participant and study process measures are associated with retention in a longitudinal tobacco cessation research study performed in Anchorage, Alaska. Specifically, we conducted a secondary analysis exploring retention among 151 Alaska Native and American Indian (ANAI) people and described our study processes using study retention categories from a recent meta-analysis. We found that our study processes influence retention among ANAI urban residents more than measures collected about the participant. For study process measures, calls where a participant answered and calls participants placed to the study team were associated with higher retention. Calls where the participant did not answer were associated with lower retention. For participant measures, only lower annual income was associated with lower retention at 6 weeks. Promoting communication from participants to the study team could improve retention, and alternative communication methods could be used after unsuccessful calls. Finally, categorizing our study retention strategies demonstrated that additional barrier-reduction strategies might be warranted.