INTRODUCTION: Research with large electronic databases, despite being relatively current, is increasingly frequent because of its advantages of being able to answer questions in a real-life conditions environment, with a considerable amount of data, with great population representativeness, relatively quickly and at low cost, if we compare it with face-to-face studies. One of the areas with the greatest development potential is that of pharmacoepidemiology. Likewise, working with these databases implies knowing a very specific methodology to minimize biases of confusion, selection (generated by lost values) or the incorrect classification of expositions and events, among others. Additionally, working with large electronic databases means taking into account aspects related to the security and confidentiality of information and knowing the existing regulations in this regard.
