Clinical epidemiology is the science andmethod of studying the optimal decisions in clinical medicine, taking into consideration the epidemiologicalcharacteristics of the patient and his/her external clinicalenvironment, the disease involved, and factors andprocedures to which the patient is exposed in his/herclinical environment, specially clinical actions.Research should be a systematic process, organizedand objective, aimed to answer the question posed.Systematic means that the scientific method is applied,for that a hypothesis or work objective is formulated fromobservations or established knowledge about a topic, dataare collected following a pre-established design, and,once analyzed and interpreted, conclusions are obtainedwhich will modify or add new knowledge to the previous,and a new cycle starts again.Organization means that all members in the researchteam 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 achievethis, it is mandatory to write a protocol specifying alldetails related to the study.The meaning of the word objective is that conclusionsobtained are not based on subjective impressions but onfacts that have been observed, measured, and analyzed,and that any prejudice the study responsibles could haveis avoided during its interpretation.
Clinical-epidemiological research may orient us about the causes of disease, the relationships among them, and the relative magnitudes of their effects. The objective of this article is to link the notion of cause with the basic clinical-epidemiological parameters.There are different models explaining causality. All of them present the possible etiologic explanations for the diseases, taking into consideration the current knowledge at the time they have been posed.We start from a purely determinist conception, understanding causality as a constant connection between two factors x and y, unique, and perfectly predictable. Currently, this model is inadequate to be applied to many diseases.Many researchers have modified the determinist model to explain the multiple causality of disease, posing the existence of associations of causal factors, more than single factors, being these associations treated as sufficient cause (i.e. as a group of minimal conditions and events that inevitably produce the disease).That determinist concept of causality is supplemented with the probabilistic concept. The theory of probability is used in it, as well as the related statistical methods, to empirically evaluate a possible association that is believed causal. As a consequence of the lack of certainty of the prediction at the individual level, the theoretical notion of cause is replaced by the empirical concept of risk factor, referring to a variable which is considered to be related to the probability that one individual develops the disease.Causal inference in epidemiology is the logic development of a theory, based on observations and arguments that attribute the presence (association) of a disease to one or more risk factors. We will follow the principles posed by B.Hill for the complex process called scientific generalization. To correctly perform this relationship between our ideas and are observations it is absolutely important to start from a correct election of the study design with which the research is undertaken.
Epidemiology develops measurements thatallow to quantify the occurrence of disease within thepopulation. There are three types of measurements:frequency measurements, explained in this article;association measurements, between the occurrence ofdisease and some characteristics, the effect of which on thedisease is what they intend to measure; and measurementsof the potential impact that modification or disappearanceof some risk factors would have on the occurrence ofdisease in the population.The first objective of epidemiological studies is theknowledge of the frequency of disease. There are threebasic measurements of frequency of a disease. Prevalencemeasures the proportion of people that has it in a givenmoment. Cumulative incidence measures the proportionof people that convert from non-sick individual to sickindividual during a specified period of time.Incidence rateis a measure oftheinstantaneous strengthof occurrence of the disease.
The use of statistics in medical articles has risen a lot during the last decades, however it is used in a thoughtless manner in many instances. Today, Statistics is the only tool that allows the medical researcher to obtain results and benefits from those studies the relationships of which can not be interpreted from a determinist perspective, because it is a branch of applied mathematics objective of which is to manage and quantify the uncertainty of the available information, to support decision taking.The objective of this article is to review the basic statistical concepts that every doctor should know to be able to perform and/or detect quality research, as well as to underline the most frequent errors committed when interpreting statistical results. We review the general concepts about data synthesis and differentiation of the different types of measurements, hypothesis testing and errors that can be committed doing it, the real meaning of the "p" value, differentiation between statistically significant and clinically relevant results, the importance of confidence intervals as a measure of significance and clinical relevance, the confusion generated between two concepts that are different as standard deviation and standard error, and the criteria that govern the selection of the adequate statistical tests to evaluate relationships between variables.
The design of an epidemiological studyincludes the procedures, methods and techniques by whichthe researcher tries to obtain valid (avoiding systematicerrors or bias) and precise (avoiding random errors)answers to the research question posed.This principal question aimed to be answered is thespecific objective of the study, which guides the election ofan adequate type of design. The objective of this article isto describe the classification criteria (finality, temporalsequence, directionality, and control of the assignation ofdifferent study factors) of the different types ofepidemiological studies (experimental, almost-experimental, and observational) and the main advantages,disadvantages, utilities and objectives of eachinvestigationdesign.
Prognosis is a description of the course of a disease from the beginning. In comparison to risk factors, prognostic factors are relatively frequent and may often be estimated by our personal clinical experience. Nevertheless, the cases of diseases usually cared for at hospitals and described in the medical bibliography are often biased samples and have the tendency to overestimate severity.Cohort studies imply follow-up of the groups of individuals over time. They are the observational studies with the highest acceptance within the scientific community, because they include the target population in the study . If we look for providing solid information, the observation of the members of a cohort , independently of what they have in common, should comply with two criteria:1. Cohorts should be observed for a significant period of time of the natural history of the event studied .2. All members in a cohort should be observed for the full follow-up period.As in any cohorts observation, studies comparing prognosis among various groups of patients may be biased if differences appear due to cohort recruitment methods, patients shifting from their initial groups, and unequal results evaluation.
The objective of etiologic research is tolook for the causes of disease, their relationships with it,and their relative magnitude on the appearance of thedisease. The observational studies (in which there is nomanipulation of the study factor), that are performed whenthe knowledge about the disease to be studied allows tospecify beforehand one or more hypothesis that can betested are called etiologic or analytic studies. The objectiveof etiologic studies is to identify risk factors for a givendisease, to estimate their effects on the appearance ofdisease, and also to suggest a possible strategy ofinterventions to diminish the appearance of disease. Casecontrol and cohort studies are the etiologic studies moreoften used, characteristics of which will be exposed in thisarticle.
Diagnosis is a process characterized byuncertainity, which the researcher can approach throughknowledge based on the theory of probability, and, assuch, it is part of the general decision-making process. Touse a test is a process that helps to confirm or refuse theinitial probability of the patient to be sick. In this article,we analyze the essential characteristics of diagnostic testsand the principles of effective evaluation of the studiesabout these tests. We explain in detail what reliability ofan instrument is, the types of reliability that there are, andhow to analyze them. So that, we introduce concepts suchas Pearson’s correlation coefficient, intra-class correlationcoefficient, and Cohen´s Kappa coefficient . Another topicdescribed in this article is measurement of validity, definingthe types of validity to be considered on an instrument.Finally, we treat the general principles that rule the designand execution of a study for the evaluation of diagnostictests, the structure followed by these studies , and mainlythe analysis, intention of which is to evaluate to whatextent that diagnostic test differentiates between subjectswith and without the disease studied. We explore theconcepts of sensitivity, specificity, predictive values, andprobability ratios, and ROC curves are explained.
A systematic review is characterized by the application of the scientific method to the evaluation of scientific literature. When a systematic review uses statistical techniques to combine and summarize the results from previous studies, it is called meta-analysis. Meta-analysis is a working tool that facilitates the realization of systematic and quantitative reviews. Its greater objectivity and rigour in comparison with the traditional reviews make that meta-analysis techniques are little by little being generalized as standard instrument to evaluate scientific evidence. In this article we detail the objectives and applications of this type of studies, as well as the stages in its preparation, including the presentation of results.
The need of scientific knowledge productionin Urology is unavoidable and desirable, despite of thedaily work complexity, overload, and conditions. Researchinitiatives should be well planned to make the limited timeand resources usually available for protocols and research projects development very rentable. In this article wedescribe the critical success predictor points for a projectand the different stages any research work consists of,from the initial question to the applicability of the results.
Publication of a scientific work is the finaland obligatory stage of any research. Among the variousexisting types of medical publications, the research originalarticle is the prototype of scientific article. Its finalityis to communicate the investigation undertaken to thereader in a coherent, clear and precise manner. With thatpurpose, the discoveries found by the authors as an answerto a hypothesis are presented and discussed.To send the original article to a biomedical journal, themanuscript should present some adequate formalcharacteristics, in addition to contain scientifically validinformation. That can be achieved by complying with therules past by the International Committee of BiomedicalJournal Editors which have been adopted by a greatnumber of scientific journals as publication requisites.The objective of this article is to describe the structureof the various parts (first page, abstract, introduction,material and methods, results, discussion, andbibliographic references) that constitute the format of theresearch original article, exposing the main adverse to beavoided during its preparation.
- Clinical research should remain linked tobasic research. In urology, it is mandatory to consider anadequate use of available resources. Translational researchis a new discipline that joins all professionals implicatedin a given research, purpose of which is the patient’sbenefit.The criteria for, limitations of, and possibilities ofjoining to translational research are well established. Itsdevelopment requires the cooperation of differentprofessionals and good scientific politics, always with thepurpose of promoting research in patients withgenitourinary diseases.
One of the most important challenges ofresearch in the health sciences is to approximate basic,clinical, and epidemiological research, and to converthospitals and outpatient clinics in nuclei of vanguard andinnovation in this field. It is not possible to develop qualityresearch without a quality clinical practice and viceversa. Because of this, all investment efforts made in thisfield will always be actions that, immediately or on thelong-term, will finally result in an improvement in thequality of patient care for the citizens, and in greaterdevelopment impulse and transfer of great amount oftechnology and innovation that is inexorably emerging inthis field. Next there is a summary of the National Plan ofScientific Research, Development and TechnologicalInnovation 2000-2003 and the role of the Institute ofHealth Carlos III in the promotion of the health science‘sresearch in Spain.
The evaluation of R+D activities and thepolitics that promote them is essential to justify theinvestment done as well as to optimize their results. In thiscontext, the evaluation should be understood as the groupof techniques and procedures that allow obtaining usefulinformation to take decisions in the field of R+D. Thisarticle has two main objectives: (i) to present the basicconcepts associated with the evaluation of research, and(ii) to offer a general and updated panoramic view ofwhich are the most frequently used methods to evaluateresearch. For that, in addition to considering the mostconventional evaluation, focused on scientific results, wealso think about the need of evaluating the impacts thatscientific results generate on the social-economic context,and that in the case of biomedical research, these may bepresented in terms of quality and life expectancy,improvementsin patient care, etc. Therefore,themotivationof present article is to give a modern and updatedperspective that allows the reader who is interested tostudy in-depth this emerging field of Science, if he/shewants.
The present article reviews the historic background of research in the Spanish University and particularly biomedical research in our country. We analyze the last set of data facilitated by the University Council and the Consejo Superior de Investigaciones Científicas.We also review the implications that the National Plan of Quality has had on university research, clearly stimulating and improving the system, and new transformations that the Organic Law of Universities brings implied, and more specifically the National System of Qualification for the access to university teaching staff, which has research work of the teachers as the essential key.Finally, we review the biomedical scientific production during the last years by topics and universities, reflecting the improvement seen during the last decade not only in quantity but also in quality, which is more important.In conclusion, the review reflects a notable change in biomedical research in our universities opening an encouraging track for the future of research.
The Framework Program for Research andTechnological Development constitutes the maininstrument the European Union has had for financingresearchsince1984.ThecurrentSixthFrameworkProgram(6FP), that covers the period 2002-2006, includes clinicalresearch among the activities subsidized at the Europeanlevel. Other research activities in the field of medicine,particularly genomics and research activities connectingbasic knowledge generation with its applications in thefield of health also receive a special emphasis. Examplesof topics open to project presentation during the frameworkprogram are: research on cancer, both at the basic andapplied and clinical levels, new diagnostic techniques,new drugs, and the fight against antibiotic resistances. Among the various types of projects that have room withinthe 6FP, the networks of excellence (NoE) and integratedprojects (IP) stand out for their importance and their effectgiving structure to the European research. Both try toreunite a critical mass of researchers and resources, togenerate knowledge in the case of the IPs, and tointerconnect experts to strengthenandextend the excellencein a specific research topic in the case of the NoE. Boththese and the more modest traditional instruments requireparticipation of groups from different countries in aconsortium, mainly from the European Communitycountries. The process of evaluation is carried out lookingat relevance criteria, scientific excellence, potential impact,and quality of the consortium, among others. Spanishresearchers, among others, are wellcome to participate inthe consortiums, coordinate projects and also to assist asexperts in the evaluations.