O valor da análise crítica da literatura para a atualização médica continuada

Abstract

Continuing medical updating is crucial for the safety and good quality of medical practice. Today, the less expensive, easy and trustful way of acquiring medical knowledge is through literature review in electronic data banks, which are available on the internet. Accordingly, a minimum knowledge on behalf of the reader is necessary to critically evaluate scientific articles and not to have his clinical practice based on information which cannot stand for the truth (1,2) . Although journals with a high "impact factor" submit the studies they receive to the analysis of competent reviewers (peer reviews), there is no guarantee that all articles published in these journals are of good quality and, in the same way, it is possible to have good studies published in journals of low "impact factor" (3)(4)(5). It is also important to know that publications do not always accuretly express the scientific truth. There are levels of study values, for instance a retrospective study is less trustful than a randomized clinical trial, that has a lower scientific value than a meta-analysis, that, in other words, is the type of publication in which the results are closer to the scientific truth of that moment, because the way the hypothesis was tested is more precise and had, in theory, less influence of other factors which could deceive the data. Thus, we have to measure the value of the published information, considering the design of each study (6) . It is important to also consider the value of the article, which is the degree of conformity with truth. The External Value refers to the possibility of applying the results in different realities (generalization). For example, an article that identifies the barriers for access to cataract surgery in a public hospital of northeast Brazil may not be totally valid to the reality of southeast or to a private clinic where the difficulties of access are possibly others. The Internal Value indicates the level in which the results of the research reflect the truth, or better, how much we can trust on the data. The Internal Value is related to the employed methodology which allow us to measure the possibility of the results being biased.Thus, the most important part of the publication that has to be carefully analysed is the description of the employed methodology for obtaining the data. It is on this item that one has to consider the issues which could deceive the results. Methodological errors are called Biases and their identification reflect how much one can trust the results of the study. The Bias can be understood as an error that does not take us to a true and biased conclusion and can also be random or systematic. In research, statistical tests detect the casualty action (random error), but not the systematic error (systematic distortion between the measure of a variable and its real value).Random Bias represent, in general, individual features of the population they are studying, features that are not controlled by the researcher and which could influence the results of the survey....

Medicine based on evidences

“…2014; 73 (1): [5][6] Medicine based on evidences Medicina baseada em evidências C ontinuing uptading was always an important requisite for a good exercise in medicine. Nevertheless, with the technological development and the great increase in options for diagnosis and treatment, it is also necessary to know how to recognize the best evidences and critically interpret them (1) . There are several knowledge available resources in the medical environment: individual communications, courses and congresses, text-books, pharmaceutical industry advertising, journals (scientific or non-scientific), internet, etc.…”