Public health informatics has in recent years emerged as a field of its own from medical informatics. Since public health informatics is newly established and also new to public health professionals, previous research in the field is relatively scarce. Even if the overlap with medical informatics is large, there are differences between the two fields. Public health is, for example, more theoretical and more multi-professional than most clinical fields and the focus is on populations rather than individuals. These characteristics result in a complex setting for development of information systems. To our knowledge there exist few systems that support the collaborative process that constitutes the foundation of public health programs. Moreover, most applications that do support public health practitioners are small-scale, developed for a specific purpose and have not gained any wider recognition.

The main objective of this thesis is to explore a novel approach to identifying the requirements for information system support with geographical information system (GIS) functionality in public health informatics. The work is based on four case studies that are used to provide the foundation for the development of an initial system design. In the first study, problems that public health practitioners experience in their daily work were explored. The outcome of the study was in terms of descriptions of critical activities. In the second study, the use case map notation was exploited for modeling the process of public health programs. The study provides a contextual description of the refinement of data to information that could constitute a basis for both political and practical decision in complex inter-organizational public health programs. In the third study, ethical conflicts that arose when sharing geographically referenced data in public health programs were analyzed to find out how these affect the design of information systems. The results pointed out issues that have to be considered when developing public health information systems. In the fourth study, the use of information systems with GIS functionality in WHO Safe Communities in Sweden and the need for improvements were explored. The study resulted in identification of particular needs concerning information system support among public health practitioners.

From these studies, general knowledge about the issues public health practitioners experience in daily practice was gained and the requirements identified were used as a starting-point for the design of information systems for Motala WHO Safe Community.

The main contributions of the thesis involve two areas: public health informatics and requirements engineering. First, a novel approach to system development in public health informatics is presented. Second, the application of use case maps as a tool for requirements engineering in complex settings such as public health programs is presented. Third, the introduction of requirements engineering in public health informatics has been exemplified. The contributions of the thesis should enhance the possibility to perform more adequate requirements engineering in the field of public health informatics. As a result, it should be possible to develop information systems that better meet the needs in the field of public health. Hence, it contributes to making the public health programs more effective, which in the long run will improve public health.