Abstract
1) Object: We have developed many kinds of medical and health information systems. These systems have huge databases now. But it was difficult for us to make evidences only with the data. We will discuss how we can make evidences with our experiences.
2) Subjects and methods: We will discuss first how we can extract evidences from cross-sectional data with an example of results of health examination of about 700,000 persons. We will discuss secondly how we can make evidence from business application system with an example of health checkup system and resident registration system in cities.
3) Results: We will show you we can get evidences from our information systems and some sampling method or follow-up systems. We have examined clinical guidelines with the evidences.
4) Discussion: It is difficult to get any evidence only with data stored in information systems which we have developed. We can extract evidences with methods clearing vias and follow-up systems.
