A variety of surveys have been conducted into patients’ and doctors’ experiences of open notes but much less is understood about the objective changes in documentation that may arise as a result of patient access. We review current research into open notes including clinicians’ reports on how they have modified their notes as a result of implementing the practice. Highlighting the potentially beneficial and harmful effects that different types of documentation changes might have on the therapeutic relationship and on patient outcomes, we argue that more research is needed to investigate objective changes in notes as a result of patient access.