Biomedical Research Cohort Membership Disclosure on Social Media.

To accelerate medical knowledge discovery, an increasing number of research programs are gathering and sharing data on a large number of participants. Due to the privacy concerns and legal restrictions on data sharing, these programs apply various strategies to mitigate privacy risk. However, the activities of participants and research program sponsors, particularly on social media, might reveal an individual's membership in a study, making it easier to recognize participants' records and uncover the information they have yet to disclose. This behavior can jeopardize the privacy of the participants themselves, the reputation of the projects, sponsors, and the research enterprise. To investigate the dangers of self-disclosure behavior, we gathered and analyzed 4,020 tweets, and uncovered over 100 tweets disclosing the individuals' memberships in over 15 programs. Our investigation showed that self-disclosure on social media can reveal participants' membership in research cohorts, and such activity might lead to the leakage of a person's identity, genomic, and other sensitive health information.