Before a new diagnostic test and before the use in clinical practice, it is necessary to know its validity. And to validate studies of diagnostic tests it is necessary they have methodological rigor in the design and applicability. In diagnostic tests we can consider two checklists: STARD for validity and QUADAS for quality.
The STARD statement defines a list of 25 questions and one flowchart to be followed for an appropriate study design, given the inclusion of patients, the order of performing the test, the number of patients receiving the test and the selected refe­rence.
The QUADAS statement consists of four key areas including: selection of patients, test under study, reference standards, and patient flow and timetable.

Currently, quality systematic reviews (with or without meta-analysis), and with a well-defined methodology, has been considered one of the best sources of available scientific evidence. They have great value (and popularity) in the cycle of generation, transmission and implementation of knowledge, both for its value per se as being the starting point of clinical practice guidelines and/or reports of health technology assessment.
But a systematic review is not good per se (as neither is a clinical trial). To have quality, it should describe the methodology in a complete and transparent manner. To check the quality of systematic reviews we have the PRISMA statement, a checklist for this type of study that replaces the QUOROM previous statement. Therefore, we already have the "prism"; now we have to use it and we have prove that it improves the quality of systematic reviews.

Clinical trials are considered the gold standard in therapeutic interventions and the key factor in these studies is randomization. The germ of these lists guide comes from the standards applied to randomized clinical trial, the gold standard of biomedical publication, and it needs to be described in detail, accurately and transparently, both the design, implementation, analysis and results. However, the information provided in the publications is often inadequate or inaccurate, and these deficiencies motivated in 1996 the development of the CONSORT statement. We are in the third generation of the CONSORT statement and we review the 25 items that are considered critical and that should be included in any report of a randomized clinical trial.
Nonrandomized intervention studies are needed when there are reasons that prevent the realization of a randomized clinical trial, but the TREND checklist should be used to communicate transparently the results. In this article we also review the 22 items of the TREND statement with a brief description of each one.

To publish less and publish better, we need good training and good resources. One of these resources is some good practice guidelines for the preparation of papers (both formal and ethical aspects). They must be guidelines disseminated and available for publishers, authors, reviewers and readers. These guidelines are known as "checklists".
These guides lists form a sea of acronyms (AGREEE, CONSORT, COREQ, MOOSE, PRISMA, REMARK, SQUIRE, STARD, STROBE, TREND, etc.) defining initiatives to improve the conduct and publication of experimental, observational diagnostic accuracy studies, forecasting, economic evaluation, clinical practice guidelines, etc.
There is considerable published information on checklists for scientific articles. In addition, some Internet resources offer useful information to readers, reviewers and editors, among highlights EQUATOR Network, acronym of Enhancing the QUAlity and Transparence Of health Research.

As in a theatre play, an article has a beginning (Introduction), middle (Methods and Results) and outcome (Discussion). In the Discussion we analyse the significance of the study findings, we highlight new and important aspects of the study and key conclusions, analyse and interpret research data according to the methodology and we specify a response (conclusion) to the question research (objective). In the Discussion we address four key areas: scientific validity, clinical relevance, novelty and clinical utility.
Care in selecting and transcribing bibliography in a scientific paper focuses on many aspects, but one essential is the rigor with which a study was conducted. References are a prominent section in a scientific paper, where the careful selection of relevant documents is an element that gives strength to theoretical exposition of the text, as well as an important source of information for the reader. It is important to know the requirements to make the references based on the "uniform requirements" (Vancouver style is the most widely used in medical science).
And finally, four sections that usually go at the end of the document and which are also of interest must be taken into account: Acknowledgments, Funding, Conflicts of interest and Annexes.

Material and methods and Results are the central and most important sections of an article, as they include the essence of critical reading, where it is possible to assess the validity (from a scientific point of view), relevance (from the clinical point of view) and applicability (in clinical practice).
The Material and methods section is the «operating instructions» of the investigation, so it is essential to expose it precisely to the extent that this section of the article is the one that causes most rejection publication. The writing of this paragraph may be literal or, perhaps better, can be structured in several sections, among which we could include the following: type of study design, subjects or patients, type of variables, population and sample, interventions and measures, statistical analysis and ethical standards.
The Results section is the «heart» of the article, but a heart that should beat at the same rate of Material and methods and always be consistent. Here we select, organize and present data using two stylistic forms: the text (with a very efficient stylistic form, clear and precise) and auxiliary elements of the text (tables, charts, figures, photographs and diagrams). Therefore, in the Results section there are two key points: to do a good data the analysis and present themselves well.

Each section of an article must be dissected in depth to understand their opportunities and threats when reading (and writing) a scientific paper. This article will address the first three paragraphs of an article: title, abstract and introduction.
The title is the first thing to read in an article, hence its importance. We must find good titles and we must know the characteristics that advise and mistakes to avoid. In the title (and throughout the text) we must observe two basic issues: the sentence length and word length, which is known as "fog index".
The abstract is a key part of the article, their business card. It is the text that usually focus the initial interest to read the full text, with the title. Its purpose is to identify the contents of the document quickly and accurately, with few words (150-250) and with a precise and concise stile. We must carefully choose appropriate keywords and translate them into English correctly. The introduction is the presentation of the work and is like a promotional text. We must know well the recommended sequence, the proper use of the literature and correct statement of objectives, but we must also avoid the most common mistakes made in this section.

If reading is a necessary step to writing, to read well scientific literature is the first step to write (and raise) properly scientific articles. Critical reading is the process of assessing and interpreting evidence from the scientific literature, systematically considering the results presented, and learn to judge whether the scientific evidence is valid (scientific rigor), important (interest in clinical practice) and applicable (in our medical environment). In this way, critical reading allows us to discriminate articles according to the strengths and weakness of the methodology used, and its purpose is to help professionals to take appropriate decision in clinical management situations.
In this article we state the basis to acquire the necessary skills for successful critical reading, as well as major resources available to learn and improve critical reading of biomedical papers: CASPe, Grupo de Trabajo de Pediatría Basada en la Evidencia, etc.

Title: Scientific communication (XIII). Basic knowledge to develop a scientific paper (8): Where to publish? The quality, relevance and impact in biomedical publications. 
After answering the two basic questions in the process of publishing a scientific paper (why and for what?), it is necessary to answer a key question: where to publish the article? Choosing the right journal in which to publish a work depends on various aspects to be taken into account, without losing track of the research process: before assessing the impact of the journal, it must have previously considered the scientific quality and clinic importance.
The essence of scientific publications should not be doing curriculum but to advance and improve healthcare. And although it is permissible to choose high impact factor journals (in the first quartile of the Journal Citation Reports), we must not fall into the "impactolatry" and its variants ("impactofilia", "impactofobia" and "impact what?"). 
The evolution of the scientific publication since the beginning of the XXI century has tried to answer the following questions about where to publish: publication in printed journals or in digital journals?, publication in Spanish or in English?, payment for publication or open access journals?; and publication in impact factor journals or other bibliometric indicators?

Peer review is an essential link in the process of publishing of the best journals and is a key quality control mechanism. It consists of the critical assessment of manuscripts submitted to journals by experts who are not part of the editorial staff, in order to measure their quality, feasibility and scientific rigor.
This article discusses the various forms of review (single-blind, double-blind and open), the criteria to become a reviewer (subject knowledge, impartiality, academic behavior, innovation and responsibility), the strengths, weaknesses and limitations of the system (slowness, arbitrariness, anonymity, lack of agreement between reviewers and differential treatment) and some fallacies that should be banished.

Besides methodologically correct, biomedical research must be ethically good, and it must meet the requirements of the four principles of bioethics: non-maleficence, justice, autonomy and beneficence. We start from the premise that "everything that is not correct from a scientific point of view is ethically unacceptable" although it is true that "not all the right things from a scientific point of view is acceptable from an ethical point of view".
The main ethical aspects of the most important scientific publications concern authorship, originality, the peer review process, publication bias, good clinical practice in research, scientific misconduct and conflicts of interest.

Statistics is an essential section for both, authors and readers of scientific literature, that offers the basis for the scientific rigor of the study and the validity of the conclusions. Knowing the subject of a scientific article helps to understand the work and knowing the principles of statistics helps to understand the methodology.
The main assumptions of the statistic that should be taken into account in the preparation of a scientific paper are: 1) describe the scientific methods with enough detail; 2) quantify the results; 3) know the meaning of the p value p; 4) does not depend exclusively of p; 5) analyze the inclusion and exclusion criteria; 6) provide the details of the randomization process; 7) provide the details of the masking process; 8) report on the complications of the treatment; 9) specify the number of observations and indicate losses; 10) specify the statistical software and statistical references; 11) define the terms and avoid using non-technical statististical terms in statistics, and 12 ) handle errors in clinical research.
Statistics should not become a religion that leads to salvation through the ritual of finding significant values of p, and then the authors reaching the promised land of publication of the paper in a high-impact journal, but properly used is a useful tool for the design and conduct of medical research.

When a scientific paper is drawn, it is necessary to organize the data so that they must be clear and patent to the reader. There should be a perfect balance between text and graphics (tables and figures) to avoid redundant information. Thus, the tables and figures are as scenery where tables work as "image data" and figures as "the image of ideas". If they are well designed and performed, they enhance the work, streamline the evidence and provide visual relaxation throughout the text. Otherwise, they get bored and distract the reader from the message.
Graphic elements should not simply be added because we have them, but we must think objectively its utility in improving the quality of information from scientific text.

Caring for the form of the article (i.e., the scrupulous respect to the specific instructions of the journal; good distribution of sections; a clean, well organized and coherent prose) is the best attribute to enhance the scientific merits of the work, and ultimately promote the acceptance, readability and ensure that the message of the study reach the readers. This article reviews the key of "form" to improve the quality of scientific publications. These are 5 qualities to be cultivated (fluency, clarity, conciseness, simplicity and attraction), 5 defects to be avoided (artifice, emptiness, claim, monotony and ambiguity), and 5 common mistakes that we must consider (abuse acronyms, foreign words, barbarisms, redundancy and grammatical problems of morphology and punctuation).

Scientific papers of biomedical journals are divided into two types: on the one hand those the authors write in a spontaneous way and then send to the journal for its publication (e.g. original articles, case reports and letters to the editor) and on the other hand those requested to the authors by the journals (e.g. editorials and reviews). While the former are subjected to peer review system, the latter have a perfect passport for publication due to their commission nature.
In this paper we review the «background» (what is said) of each major type of article, reviewing with particular depth the different sections of original articles: title, abstract, introduction, materials and methods, results, discussion, bibliography. Knowing the "background" of the articles is key to start the preparation and submission of a manuscript to a biomedical journal.

The ethics of scientific communication implies that scientists gather and transmit information, so that publishing is something inherent to the work of the scientist. The publication and dissemination of research results is, therefore, a necessity. This involves a prior process of reflection and self-criticism before starting work in a scientific paper. Once considered useful publication, the preparation of an article can be summarized in ten key steps: 1) review the scientific literature; 2) select the appropriate journal to which to send the article and check the "Instructions for authors"; 3) advocate the authorship; 4) gather research data; 5) select the type of item; 6) write the first draft; 7) write the following drafts and the final version of the article; 8) send the article; 9) know the editor's decision, and 10) correct the proofs.