The concept of evidence-based medicine (EBM) has promulgated among healthcare professionals in recent years, on the other hand, the problem of underuse of useful clinical evidence is coming to be important. This is called as evidence-practice gap. The major concern about evidence-practice gap is insufficient implementation of evidence-based effective treatment, however, the perspective can be extended to measures to improve drug safety and prevention of drug related adverse events. First, this article reviews the characteristics of the database of receipt (healthcare claims) and the usefulness for research purpose of pharmacoepidemiology. Second, as the real example of the study on evidence-practice gap by using the receipt database, the case of ergot-derived anti-Parkinson drugs, of which risk of valvulopathy has been identified, is introduced. The receipt analysis showed that more than 70% of Parkinson's disease patients prescribed with cabergoline or pergolide did not undergo echocardiography despite the revision of the product label recommendation. Afterwards, the issues of pharmaceutical risk management and risk communication will be discussed.