The objective of this study is to formulate a clearer picture of how a regional healthcare information system affects the completeness of patient health care and health care delivery. The purpose is to study how the implementation of regional health information systems has influenced outcomes in health care delivery in one hospital area in Finland. The essential concepts in this study are health care information systems and outcomes. The research consists of four different phases. Research material will be processed through qualitative and quantitative research methods and statistical tests.