Brigit O'Sullivan Brigit O'Sullivan is a user researcher at NHS Digital. Copyright NHS Digital User Researcher Brigit is a user researcher at NHS Digital. Blogs By Brigit O'Sullivan. 12 October 2020 NHS App: Conducting user research in lockdown Conducting user research remotely is challenging but can yield unexpected benefits. Brigit O’Sullivan, User Researcher at NHS Digital, describes what she learned working as a user researcher for the NHS App during lockdown..