Bridging the information gap in patient transition (BIG) is a Norwegian research project, funded by the Norwegian Research Council (grant no. 196365). The overall aim with the project is to obtain knowledge on collaboration between nurses in home health care, general practitioners (GPs) and hospitals concerning patients that are in need of home health care. More specifically we study how the introduction of electronic messaging (e-messaging) affects the collaboration. We study e.g. how work practices are changed as emessaging are integrated in healthcare practice, consequences for quality of care, and unintended consequences of the introduction of e-messages. Well-functioning information exchange and communication is important in order to provide high-quality and efficient healthcare services. This is in particular an important issue where the patient is in contact with many healthcare providers. Health information technologies are seen as a means to improve information exchange and communication, and hence further collaboration. Theoretically the study draws eclectically on perspectives from nursing and health informatics, CSCW (computer-supported cooperative work), STS (science and technology studies) and medical sociology. Conceptually we draw on a broad framework representing continuity of care, integrated care and patient safety, as well as clinical communication and collaboration. We have chosen an explorative and descriptive design, and apply a mixedmethod approach in our study. Interviews with a range of involved healthcare providers, as well as participant observations of homecare nursing form the qualitative part of the data material. Furthermore, a national survey has been conducted, and form the quantitative part. The study results, currently under analysis, underpin the informational complexity in the actors' collaboration. Introduction of e-messaging connects health personnel across different organizational structures, and strengthen communication and information exchange as indented. But it does also lead to unintended consequences, in turn making it necessary to address new issues related to how to organize the e-messaging. We have identified organizational, technological and professional possibilities and challenges that impact the collaboration and interaction. Our findings will be elaborated in future publications.