Patient safety work relies on the service provider's ability to monitor the levels of patient safety achieved, identify where improvements are needed and follow the impact of implemented interventions. Trigger tools - means for performing focused medical records reviews either manually or automatically, are a strong candidate for supporting these tasks. This report examines the research evidence on the IHI Global Trigger Tool (GTT) and presents experiences accumulated in Finland during implementation of the tool in the hospital environment, as well as experimentations for further developments. In addition, the up-to-date evidence and future prospects on automated trigger tools are reviewed and discussed. The report aims to serve healthcare management and clinical staff working with patient safety issues on the organisational level, by providing background evidence with regard to trigger tool methodology and its implementation requirements. The report constitutes useful reading also for policy makers, developers and researchers in the fields of patient safety, healthcare quality and health information technology.