Inter-observer agreement on levels of evidence in radiology articles.

Levels of evidence (LE) are established through a hierarchical classification of studies according to their design. At present, there are many heterogeneous LE classifications, and this hampers their applicability. Our study aims to identify which LE classification has the best interobserver concordance for radiology articles. For this purpose, an interobserver agreement analysis were performed on 105 original articles applying two NE scales (Oxford Center of Evidence Based Medicine (OCEBM) y National Health and Medical Research Council (NHMRC)). The inter-rater agreement of the LE assigned after reading the abstracts was good when using the OCEBM scale (K = 0.679), and somewhat lower with the NHMRC (K = 0.577 -moderate-). All differences were statistically significant (P < .000). So, in conclusion, of the two scales analysed (OCEBM and NHMRC), the OCEBM led to the strongest level of inter-rater agreement.

Bibliometric indicators to evaluate scientific activity. / Indicadores bibliométricos para evaluar la actividad científica.

Bibliometric indicators have been devised to quantify scientific production and to try to evaluate its impact in the community. In general, bibliometric indicators can be classified according to whether the unit of analysis is the author (individual or group) or journal. The most widely used indicators for authors are those that measure an individual author's production, such as the Crown index or the h-index and its derivatives (e-index, h5-index, and the absolute or Ab-index, among others). The bibliometric indicators devised to try to evaluate journal quality are associated with Journal Citation Reports (e.g., impact factor, field-weighted citation impact, Eigenfactor, and article influence) or with Scopus (Scimago Journal Rank (SJR), source normalized impact per paper (SNIP), and CiteScore). This article describes the main bibliometric indicators, explains how they are calculated, and discusses their advantages and limitations.

Fluoroscopic studies of the upper gastrointestinal tract: techniques and indications. / Estudios telemandados con control fluoroscópico del tracto digestivo superior: Técnicas e indicaciones.

Fluoroscopic studies of the gastrointestinal tract are becoming increasing less common due to the introduction of other imaging techniques such as computed tomography and magnetic resonance imaging and to the increased availability of endoscopy. Nevertheless, fluoroscopic studies of the gastrointestinal tract continue to appear in clinical guidelines and some of their indications are still valid. These studies are dynamic, operator-dependent examinations that require training to obtain the maximum diagnostic performance. This review aims to describe the technique and bring the indications for this imaging modality up to date.

[Elaboration and critical evaluation of clinical guidelines]. / Elaboración y evaluación crítica de las guías de práctica clínica.

Clinical guidelines are documents to help professionals and patients select the best diagnostic or therapeutic option. Elaborating guidelines requires an efficient literature search and a critical evaluation of the articles found to select the most appropriate ones. After that, the recommendations are formulated and then must be externally evaluated before they can be disseminated. Even when the guidelines are very thorough and rigorous, it is important to know whether they fulfill all the methodological requisites before applying them. With this aim, various scales have been developed to critically appraise guidelines. Of these, the AGREE II instrument is currently the most widely used. This article explains the main steps in elaborating clinical guidelines and the main aspects that should be analyzed to know whether the guidelines are well written.

[Critical reading of analytical observational studies]. / Lectura crítica de artículos observacionales.

Analytical observational studies provide very important information about real-life clinical practice and the natural history of diseases and can suggest causality. Furthermore, they are very common in scientific journals. The aim of this article is to review the main concepts necessary for the critical reading of articles about radiological studies with observational designs. It reviews the characteristics that case-control and cohort studies must have to ensure high quality. It explains a method of critical reading that involves checking the attributes that should be evaluated in each type of article using a structured list of specific questions. It underlines the main characteristics that confer credibility and confidence on the article evaluated. Readers are provided with tools for the critical analysis of the observational studies published in scientific journals.

[Key aspects in interpreting clinical trials in radiology]. / El ensayo clínico en Radiología: claves para su interpretación.

A clinical trial is an experimental study to evaluate the efficacy and safety of a treatment or diagnostic technique in human beings. To ensure the methodological quality of a clinical trial and the validity of its results, various checklists have been elaborated to identify biases that could invalidate its conclusions. This article focuses on the points we need to consider in the critical evaluation of a clinical trial. We can usually find this information in the "materials and methods" and "results" sections of articles. Randomization, follow-up (or analysis of losses), blinding, and equivalence between groups (apart from the intervention itself) are some key aspects related to design. In the "results" section, we need to consider what measures of clinical efficacy were used (relative risk, odds ratio, or number needed to treat, among others) and the precision of the results (confidence intervals). Once we have confirmed that the clinical trial fulfills these criteria, we need to determine whether the results can be applied in our environment and whether the benefits obtained justify the risks and costs involved.

[Introduction to critical reading of articles: study design and biases]. / Introducción a la lectura crítica de artículos: diseño de estudios y sesgos.

The critical evaluation of an article enables professionals to make good use of the new information and therefore has direct repercussions for the benefit of our patients. Before undertaking a detailed critical reading of the chosen article, we need to consider whether the study used the most appropriate design for the question it aimed to answer (i.e., whether the level of evidence is adequate). To do this, we need to know how to classify studies in function of their design (descriptive or analytical; prospective or retrospective; cross-sectional or longitudinal) as well as their correlation with the levels of evidence. In critical reading it is also important to know the main systematic errors or biases that can affect a study. Biases can appear in any phase of a study; they can affect the sample, the development of the study, or the measurement of the results.

[The six steps necessary in elaborating critically appraised topics]. / Los 6 pasos necesarios para elaborar Critically Appraised Topics.

Different types of critically appraised topics (CATs) can be elaborated in diagnostic imaging: comparison of diagnostic tests, evaluation of techniques for early detection (screening), economical analyses, or therapeutic aspects, among others. Their design will vary in function of the question they aim to answer. For example, for treatment evaluation, clinical trials are the best, but if there are secondary studies (systematic reviews or meta-analyses) that synthesize information from several studies, the results will be more important and the scientific conclusions will be more relevant. Regardless of the study design used, the elaboration of a CAT will involve six steps: 1) question; 2) systematic and efficient bibliographic search; 3) levels of evidence (choosing the articles that have the best level); 4) critical reading of the articles chosen; 5) applying conclusions to the context, and 6) recommendations. In this article, we will describe these steps and the nuances for different types of studies in each step.

[Critically appraised topics (CATs): a new publishing opportunity in Radiología]. / Critically Appraised Topics: una nueva oportunidad de publicación en Radiología.

Physicians need fast access to quality information about the best diagnostic tests and treatments in each case. To meet this need, a new publishing format has emerged. Critically appraised topics (CATs) are elaborated following the five steps of evidence-based medicine. CATs are structured summaries of research articles that deal with a specific clinical query, presenting a critical evaluation of the best evidence available to support the validity of the available options. CATs have proven useful in teaching evidence-based radiology and this publishing format is becoming more common. Radiology CATs can be found on medical websites and in journals, including those dedicated to general medicine as well as those specifically dedicated to radiology. Radiología encourages the publication of CATs because we consider that they can be useful for daily decision making.

[Evidence-based radiology for diagnostic imaging: what it is and how to practice it]. / Radiología basada en la evidencia en el diagnóstico por imagen: ¿qué es y cómo se practica?

Evidence-based radiology is defined as the decision that results from integrating clinical information to select the most appropriate imaging test on the basis of the best available evidence, the physician's experience, and the patient's expectations. The practice of evidence-based radiology consists of five steps: formulating the question, performing an efficient search of the literature, critically evaluating the literature, applying the results of the search and evaluation while taking into account our experience and the patient's values, and evaluating the results obtained within our own practice. In diagnostic imaging, the number of resources available for evidence-based radiology is increasing: apart from books, articles, and web pages on this subject, evidence-based radiology is receiving more attention at diagnostic imaging conferences. The principles of evidence-based radiology will help promote the appropriate use of resources, greatly benefiting patients (decreasing the use of examinations that use ionizing radiation), professionals (less overload), and managers (more efficient use of resources).