Metodo

Parrafo 1

SUMMARY 
introduction: in the era of evidence-based medicine, one of the most important skills a physician needs is the ability to analyze scientific literature critically. this is necessary to keep medical knowledge up to date and to ensure optimal patient care. the aim of this paper is to present an accessible introduction into critical appraisal of scientific articles TRADUCCION:

RESUMEN
introducción: en la era de la medicina a base de pruebas, una de las habilidades más importantes que un médico necesita es la capacidad de analizar la literatura científica críticamente. esto es necesario para guardar el conocimiento médico actualizado y asegurar el cuidado del paciente óptimo. el objetivo de este papel es presentar una introducción accesible en la apreciacióncrítica de artículos científicos.

Parrafo 5 (parte 1)….. La parte 2 es de karla

METHODS
This important section bears a certain resemblance to a cookbook. the description of the procedures should give the reader "recipes" that can be followed to repeat the study. here are found the essential data that permit appraisal of the study´s validity. the methods section can be divided into subsectionswith their own headings: for example, laboratory techniques can be described separately from statistical methods.

The methods section should describe all stages of planning the composition of the study sample(e. g.. patients, animals, cell lines), the execution of the study, and the statistical methods: Was a study protocol written before the study commenced? Was the investigation preceded by apilot study? Are location and study period specified? it should be stated in this section that the study was carried out with the approval of the appropriate ethics committee. The most important element of a scientific investigation is the study design. if for some reason the design is unacceptable, then so is the article, regardless of how the data were analyzed 

The choice of study designshould be explained and depicted in clear terms. If important aspects of the methodology are left undescribed, the reader is advised to be wary. If , for example, the method of randomization is not specified, as is often the case, one ought not to assume that randomization took place at all. The statistical methods should be lucidly portrayed and complex statistical parameters and proceduresdescribed clearly, with references to the specialist literature. Box 1 contains further questions that may be helpful in evaluation of the methods section

Study design and implementation are described by altman, Trampisch and windeler, and klug et al. In experimental studies, precise depiction of the design and execution is vital. The accuracy of a method, i. e. its reliability (precision) and validity(correctness), must be stated. The explanatory power of the results of a clinical study is improved by the inclusion of a control group (active, historical, or placebo controls) and by the randomized assignment of patients to different arms of the study. The quality can also be raised by blinding of the investigators, which guarantees identical treatment and observation of all study participants.A clinical study should as a rule include an estimation of the required number of patients (case number planning) before the beginning of the study. More detail on clinical studies can be found, for instance, in the book by Shumacher and Schulgen. International recommendations specially formulated for the reporting of randomized, controlled clinical trials are presented in the most recentversion of the CONSORT statement (consolidated standards of reporting trials)

Epidemiological investigations can be divided into intervention studies , case-control studies, cross-sectional studies, and ecological studies. table 1 outlines what type of study is best suited to what situation. One characteristic of a good publication is a precise account of inclusion and exclusion criteria. how...