Facebook: an effective tool for participant retention in longitudinal research

Background  Facebook is currently one of the world's most visited websites, and home to millions of users who access their accounts on a regular basis. Owing to the website's ease of accessibility and free service, demographic characteristics of users span all domains. As such, Facebook may be a valuable tool for locating and communicating with participants in longitudinal research studies. This article outlines the benefit gained in a longitudinal follow‐up study, of an intervention programme for at‐risk families, through the use of Facebook as a search engine. Results  Using Facebook as a resource, we were able to locate 19 participants that were otherwise ‘lost’ to follow‐up, decreasing attrition in our study by 16%. Additionally, analysis indicated that hard‐to‐reach participants located with Facebook differed significantly on measures of receptive language and self‐esteem when compared to their easier‐to‐locate counterparts. Conclusions  These results suggest that Facebook is an effective means of improving participant retention in a longitudinal intervention study and may help improve study validity by reaching participants that contribute differing results.