[Clinical research in urology and scientific methodology]

Clinical epidemiology is the science and method of studying the optimal decisions in clinical medicine, taking into consideration the epidemiological characteristics of the patient and his/her external clinical environment, the disease involved, and factors and procedures to which the patient is exposed in his/her clinical environment, specially clinical actions. Research should be a systematic process, organized and objective, aimed to answer the question posed. Systematic means that the scientific method is applied, for that a hypothesis or work objective is formulated from observations or established knowledge about a topic, data are collected following a pre-established design, and, once analyzed and interpreted, conclusions are obtained which will modify or add new knowledge to the previous, and a new cycle starts again. Organization means that all members in the research team know perfectly what to do during the whole study, apply the same definitions and criteria to all participants, and act in identical way in front of any doubt. To achieve this, it is mandatory to write a protocol specifying all details related to the study. The meaning of the word objective is that conclusions obtained are not based on subjective impressions but on facts that have been observed, measured, and analyzed, and that any prejudice the study responsibles could have is avoided during its interpretation.