Wikipedia:Cómo identificar fuentes confiables (medicina)

This is an explanatory essay about the Wikipedia:Identifying reliable sources (medicine) policy. This page provides additional information about concepts in the page(s) it supplements. This page is not one of Wikipedia's policies or guidelines as it has not been thoroughly vetted by the community.

These are some Frequently Asked Questions about Wikipedia's guidelines on sourcing for medical content, manual of style for medicine-related articles, and how the guidelines and policies apply to biomedical content.

Yes, but the guidelines for medical information follow the same broad principles as the rest of Wikipedia. Examples of this include the requirement for reliable sources and the preference for secondary sources over primary sources. These apply to both medical and non-medical information. However, there are differences in the details of the guidelines, such as which sources are considered reliable.

Different types of sources have different strengths and weaknesses. A type of source that is good for scientific information is not usually as reliable for political information, and vice versa. Since Wikipedia's readers may make medical decisions based on information found in our articles,^[1] we want to use high-quality sources when writing about biomedical information. Many sources that are acceptable for other types of information under Wikipedia's general sourcing guideline, such as the popular press, are not suitable sources for reliable medical information.^[2][3][4] (See also: WP:MEDPOP and WP:WHYMEDRS)

MEDRS-compliant sources are required for all biomedical information. Like the policy on the biographies of living people ("BLP"), MEDRS applies to statements and not to articles: biomedical statements in non-medical articles need to comply with MEDRS, while non-medical statements in medical articles do not need to follow MEDRS. Also like BLP, the spirit of MEDRS is to err on the side of caution when making biomedical statements. Content about human biochemistry or about medical research in animals is also subject to MEDRS if it is relevant to human health.

Probably not. Most peer-reviewed articles are not review articles. The very similar names are easily confused. For most (not all) purposes, the ideal source is a peer-reviewed review article.

Primary sources aren't completely banned, but they should only be used in rare situations. An individual primary source may be flawed, such as being a clinical trial that uses too few volunteers. There have been cases where primary sources have been outright fraudulent. Furthermore, a single primary source may produce a different result to what multiple other primary sources suggest, even if it is a high-quality clinical trial. Secondary sources serve two purposes: they combine the results of all relevant primary sources and they filter out primary sources that are unreliable. Secondary sources are not infallible, but they have less room for error than a primary source.

This follows a principle that guides the whole of Wikipedia. If a company announces a notable new product, Wikipedia would not cite a press release on the company's website (a primary source) but instead would cite a newspaper article that covers it (a secondary source). The difference with medical information is that the popular press are not suitable sources.

Whenever possible, you should cite a secondary source such as:

• a review article
• a meta-analysis
• a high-quality textbook

Primary sources might be useful in these common situations:

• when writing about a rare disease, uncommon procedure, etc., for which no high-quality secondary literature is available, or for which the available secondary sources do not cover all of the information normally included in an encyclopedia article.
• when mentioning a famous paper or clinical trial that made a recognized substantial impact, as part of a purely historical treatment of a topic.
• when describing major research that has made a significant impact (i.e., continued and substantial coverage). While recent research results are normally omitted, it is sometimes necessary to include them for WP:DUE weight. In this case, it is usually preferable to read and cite the primary scientific literature in preference to WP:PRIMARYNEWS sources. Later, these primary sources can be replaced or supplemented with citations to high-quality secondary sources.

The popular press includes many media outlets which are acceptable sources for factual information about current events, sometimes with significant caveats. It also includes media outlets which are discouraged in all cases because the quality of their journalism is inadequate. However, even high-quality media outlets have disadvantages in the context of medicine.

Firstly, news articles on medicine will frequently be reporting a new medical primary source, such as the results of a new study. This means that they are effectively acting as a primary source, which as explained above makes those articles generally unsuitable for medical information. These articles also tend to omit important information about the study. If a medical primary source is to be cited at all, the academic paper should be cited directly.

Secondly, media coverage of medical topics is often sensationalist. They tend to favor new, dramatic or interesting stories over predictable ones, even though studies that reflect the current scientific consensus tend to be predictable results. They tend to overemphasize the certainty of any result, such as reporting a study result as a conclusive "discovery" before it has been peer-reviewed or tested by other scientists. They may also exaggerate its significance; for instance, presenting a new and experimental treatment as "the cure" for a disease or an every-day substance as "the cause" of a disease. The sensationalism affects both which stories they choose to cover and the content of their coverage.

High-quality media outlets can be good sources of non-medical information in an article about a medical topic. Another acceptable use is using a popular press article to give a plain English summary of an academic paper (use the |laysummary= parameter of {{cite journal}} for this).

Not necessarily. PubMed is merely a search engine and the majority of content it indexes is not WP:MEDRS. Searches on PUBMED may be narrowed to secondary sources (reviews, systematic reviews, meta-analyses, etc.) so it is a useful tool for source hunting.

It is a common misconception that because a source appears in PubMed it is published by, or has the approval of, the National Institutes of Health (NIH), National Center for Biotechnology Information (NCBI), or the US government. These organisations support the search engine but lend no particular weight to the content it indexes.

Quackwatch is a self-published website by an author who is an expert in problems with complementary and alternative medicine. Whenever possible, you should use a scholarly source instead of Quackwatch. However, if no scholarly sources are available, and the subject is still notable, then it might be reasonable to cite Quackwatch with WP:INTEXT attribution to the POV.

As of 2014, there are concerns regarding positive bias in publications from China on Traditional Chinese Medicine.^[5][6] Such sources should be used with caution. The problem also includes issues with the academic system in China.^[7]

Yes, but again only with WP:DUE weight. Unlike other branches of the National Institutes of Health, which are generally accepted as authoritative in their fields, NCCAM has been the focus of significant criticism from within the scientific community.^[8] Whenever possible, you should cite the established literature directly.

MEDRS contains a section about finding sources which may be helpful. Alternatively, a more experienced editor may be able to help you find them (or to confirm that they do not exist).

A fringe medical claim is one that differs significantly from the prevailing views or mainstream views in the scientific medical community. This is similar to Wikipedia's general definition of a fringe claim. A claim can still be a fringe medical claim even if it has a large following in other areas of public life (such as politics and the popular press).

When fringe claims have been widely reported in the press, have a large popular following, and/or have a long history, it may be appropriate to describe them in terms of that reporting, popularity, or history. However, weight should be determined by MEDRS-compliant sources, and the context (or lack thereof) should not make implications about medical statements that are not supported by such sources. Guidance on the additional considerations relevant to fringe subjects can be found at WP:FRINGE, as well as at other places such as WP:WEIGHT and WP:EXCEPTIONAL.

In the case of alternative medicine, medical statements are often derived from an underlying belief system, which will include many propositions that are not subject to MEDRS. These propositions are subject to the usual sourcing requirements and the usual requirements for determining fringe status.

There are three possible situations:

• No evidence exists, either became no studies for the treatment have been published, or because the studies published are too small or weak to draw any conclusions.
• Evidence exists, and it shows no effect.
• Evidence exists, and it shows an effect.

In the first case, we cannot say that it does not work, but we can say that there is no evidence to determine whether it works. After multiple, high-quality independent studies have been published, the understanding may transition from "no evidence" to "some evidence" of either an effect or no effect. You should follow the lead of review articles and other secondary sources for determining when this threshold has been crossed.

Reports may conflict with each other. For example, a clinical trial may produce no evidence of an effect, but the treatment's manufacturer might produce testimonials claiming a positive effect. You should follow the lead of review articles and other secondary sources for determining how to balance these claims.

In other words, is it necessary to say in the article's text the source which supports a medical statement (with attribution)? Or can it simply be stated as an unchallenged fact, with the source only mentioned in the citation (without attribution)? A statement without attribution will come across as being a stronger claim than one with attribution.

A result or statement from a reliable secondary source should be included without attribution if it is not disputed by any other recent secondary sources. You should do a search to check that the secondary source you are citing is the most up-to-date assessment of the topic.

If there have been two recent secondary sources that contradict each other, then you should attribute the disputed findings. On the other hand, if the findings of one or more recent secondary sources are disputed by one or more secondary sources from many years ago, but not by any recent ones, the recent findings can be stated without attribution. You should also take into account the relative weight secondary sources have. For example, Cochrane Collaboration reviews provide stronger evidence than a regular secondary source.

In the rare cases where primary sources can be used, they should be attributed.

It is common for scientific publications to say something like this, either directly or indirectly. There are several reasons for this. It could be argued that more research is always a bonus, even if the topic has already been thoroughly researched. Sometimes, these statements may be made partly because authors need to convince readers that the topic is important in order to secure future funding sources. As such, saying this does not communicate much information, and it may also mislead readers into thinking that the existing information on a topic is less reliable than it really is.

As noted above, Quackwatch does not meet the usual standard as a reliable source, but it can be used (with attribution) for information on a topic of alternative and complementary medicine if there are no scholarly sources available for the same purpose. The guidelines on fringe theories includes the concept of parity: if a notable fringe theory is primarily described by self-published sources, then verifiable and reliable criticism of the fringe theory does not need to be published in a peer-reviewed journal. It only needs to come from a better source.

Full, searchable list of all tutorials - training materials in HTML, PDF and Video formats

YouTube channel for the National Library of Medicine: Tutorial videos from the National Center for Biotechnology Information (NCBI), part of the U.S. National Library of Medicine. Includes presentations and tutorials about NCBI biomolecular and biomedical literature databases and tools.

PubMed User Guide - FAQs

NLM Catalog Help - This book contains information on the NLM Catalog, a database which provides access to NLM bibliographic data for journals, books, audiovisuals, computer software, electronic resources, and other materials via the National Center for Biotechnology Information (NCBI) Entrez retrieval system. The NLM Catalog includes links to full text materials and the library's holdings in LocatorPlus, NLM's online public access catalog.

NLM Catalog (rev. December 19, 2019).

Overview

FAQs

Searching NLM Catalog

For full comprehensive instructions, go to: Searching for Journals in NLM Catalog

If you know the full or abbreviated name for a journal, and you want to see if it is indexed in MEDLINE, see the instructions at searching by journal title, which I will also reproduce here:

If you know the journal’s exact title, enter it in the NLM Catalog search box followed by the field qualifier [jo].

Example:
The Journal of Supportive Oncology [jo]
Results = 1 record retrieved:
The Journal of Supportive Oncology

If you know the journal’s NLM Title Abbreviation, enter it in the NLM Catalog search box, followed by the field qualifier [ta].

Example:
n engl j med [ta]
Results = 1 record retrieved:
The New England journal of medicine

Via a search of the NLM Catalog: List of Abridged Index Medicus journals, also known as "Core clinical journals".

Stand alone list: List of current Abridged Index Medicus (AIM) journals (118 journals as of 5 May 2020)

Search the NLM Catalog using jsubsetim[All Fields] to find all Index Medicus journals (5021 journals as of 29 May 2020); or go directly to the search results for all Index Medicus journals. (Note that immediately above "Search Results" on that page, you can change the default "20 per page" to as many as 200 results per page, and you can change how the results are "sorted", e.g., if you are looking for a specific journal, you can sort by Title, instead of the default.)

====Create a list of all journals indexed in MEDLINE}} Search the NLM Catalog using currentlyindexed[All] to find all journals indexed in MEDLINE (5266 journals as of 29 May 2020); or go directly to the search results for all journals indexed in MEDLINE. (Note that immediately above "Search Results" on that page, you can change the default "20 per page" to as many as 200 results per page, and you can change how the results are "sorted", e.g., if you are looking for a specific journal, you can sort by Title, instead of the default.)

MEDLINE, PubMed, and PMC (PubMed Central): How are they different?

Most scholarly journals are behind paywalls. Some options to access these articles include visiting a local university library, visiting The Wikipedia Library, and WikiProject Resource Requests.

Note that paywalled articles are frequently pirated and made available on the open web. When linking to a journal article, care must be taken not to link to such a pirate copy, as such a link would be a copyright violating link in contravention of Wikipedia's policy. In general if you find such a copy and it is not accompanied by text explicitly stating that it is made available with the permission of the copyright holder, assume that it is potentially infringing, and do not link to it. This holds for all edits in Wikipedia, not just in article space.

Search for the title of the article on Google Scholar. On the results page, click on "All n versions" (where n = the number of available versions of that article) at the bottom of a listing. The resulting page might contain PDF or HTML versions of the article.

Consult Unpaywall.org for journal articles available without a subscription. Install the UnPaywall extension for Chrome or Firefox to immediately identify articles with a free version. After you install the extension, look to the right side of the page (when you are on the website for an article) for either a grey locked symbol (no free version) or a green unlocked symbol (click on that symbol to access the full text version of the article).

An article by librarian John Mark Ockerbloom, titled, "Why Pay for What’s Free? Finding Open Access and Public Domain Articles" offers helpful suggestions.^[9]

Almost all medical articles are indexed by the PubMed search engine and have a Digital object identifier (DOI) assigned to them. All articles included in PubMed are assigned an eight-digit PubMed identifier (PMID). These identifiers can be used to refer to articles, which is preferred to URLs as it makes a reliable link which is resilient to changes beyond our control – i.e. the publisher being acquired by another publisher and it's "normal" web URLs changing as a consequence.

Once you have the PMID, there are a number of tools such as this one which you can use to generate a full citation automatically.

In article references, the "doi" and "pmid" parameters are preferred to the "url" parameter for such reasons.

On Talk pages, when referring to journal articles, is it good practice to make any link using these types of identifier also:

• Typing "[[PMID:dddddddd]]", where dddddddd is a PMID, will create a link to the indicated article.
• Any DOI can be turned into a resolvable web address by prepending "https://doi.org/" to it (e.g. https://doi.org/10.1136/bmj.c6801).

See WP:MEDCOI.

See WP:PAID.

• WikiProject Medicine's Talk Page
• Wikipedia:Why MEDRS?