Along with the continuously increasing sophistication and refinement of diagnostic procedures and therapeutic processes, the risk of Adverse Events occurring during a patient's hospitalization is also steadily rising up.

Most of the modern medications have a powerful therapeutic impact balanced by equally threatening poisonous potential side effects. Thus the risk of Adverse Drug Events (ADE) is rocketing, partly due to medication errors.

That is why Quality of Care and Patient Safety have become a general concern shared by a large community of healthcare professionals and patients.

Different strategies have been tried for tracking ADEs: reporting systems have proven to be useful but they are not exhaustive; records and chart reviews are effective in the detection of ADEs and for an evaluation of their prevalence, but these methods are time-consuming and their reproducibility is questionable. Automatic detection of ADE is still in the research domain.

Nevertheless, at the bottom line, all the teams in the world are facing identical problems: how to reliably detect ADEs, how to efficiently prevent them. War stories about ADEs are all alike, whatever the country and whatever the setting: hemorrhage following an inattentive prescription of NSAID on a bleeding ulcer, renal insufficiency after heparin treatment, reactions to antibiotics and antiviral drugs, etc.

Properly managing the modern therapeutic drugs requires mastering a large quantity of information and a high level of complex knowledge, both probably exceeding human capacities. Therefore Information and Communication Technologies (ICT) are called in for additional help to access medical records, manage the data, enhance the knowledge, perform statistical analyses, and provide Decision Support.

But despite this powerful technology support many problems remain.

The characteristics of the Electronic Health Records (EHR) vary according to the suppliers, the hospitals, the countries. Coding systems can be different. Norms and standards vary from place to place. The extraction and exploitation of medical data from different sources then appear as a real challenge and cannot be solved without the definition of common data models, standard references, classifications and taxonomies.

The classification of drugs is in itself a tower of Babel: brand names, commercial names, ATC codes, various dosages, regimens, routes of administration, pharmacological effects, potential ADE or allergies, etc. The knowledge is mastered by a limited community of experts while the complexity of the interactions and the frequency of the side effects would require that this knowledge be shared by a large number of health-care professionals and by the patients themselves.

Moreover, hospitals are much more than a mere technological setting: they are organized by administrative managers, they are ruled by physicians and nurses who are not robots, they treat citizens unwillingly playing the patient role. That is why organizational and human factors must be carefully studied as they can be at the origin or contribute to the occurrence of an ADE.

The new possibilities offered by statistical methods, data mining applications able to exploit large amount of records open a new era in the identification of abnormal hospitalization stays and detection of potential ADEs. Exploitation and screening of free-text documents such as letters and reports are now possible by means of semantic mining applications, providing new sources of patient information.

When looking at the papers gathered in this book, it appears that the approaches used to identify and prevent ADE are diverse but confronted to similar problems of codification, data exploitation, statistical analysis, etc. The ICT bring in powerful resources but they have to be driven by clear scientific objectives.

This workshop gathers knowledgeable and active persons in the domain, who are currently working at solving the problems. This is the opportunity to confront the ideas and the experiences stemming from various continents, and particularly from several EU projects financed to contribute to the resolution of the ADE problem. It is the occasion to find common ways for solving some of the difficulties everyone is sharing and make progress happen. Many thanks to Prof. David Bates, Prof. Johanna Westbrook for their participation and their keynotes; to Prof. Peter Elkin and Prof. André Kushniruk for their support and their clarifying interventions; to all the participants to the workshop; and to the European Commission which, by funding European Projects on this topics, allowed the organization of this workshop and the edition of this book.

Régis Beuscart, Werner Hackl and Christian Nøhr (Editors), September 2009