Wikipedia in a health sciences context

To continue with the topic of locating and assessing background resources for the clinical question, it may be useful to explore the appropriateness of a resource such as Wikipedia. The relevance and quality/reliability of Wikipedia entries are issues that are likely of central interest to the larger health sciences library community. This clinical case presents an opportunity to take a look at the type of medical information present in Wikipedia. To get a quick snapshot, let’s look at the first five medical concepts presented in Table 1 of the case study.

Respiratory failure -- this entry is a stub, i.e. “too short to provide encyclopedic coverage” of the topic. The entry describe two types of respiratory failure, causes, and one sentence on treatment. While the entries that are linked to for the causes tend to be fairly lengthy and descriptive, with links to external references, this particular entry is not clinically useful as the information presented is sparse and not clinically detailed.

Ventilator-associated pneumonia (VAP) – a more in-depth entry than Respiratory Failure, discussing the symptoms and signs, diagnosis, pathophysiology, microbiology, treatment, prevention and epidemiology and prognosis of VAP. For the purposes of background reading to understand this medical concept, there seems to be enough information to obtain a clear "picture" of the condition. Ideally, we might prefer to see more external references than just the ATS/IDSA Guidelines, but these guidelines are a concrete start. Also, the guidelines are available with free full-text online, but that link is not yet included in the entry. Interestingly enough, the last change made to the article as of this posting was removing its status as a stub. Quite a difference between the respiratory failure and this one.

Acinetobacter – the length of this entry is between that of the entry for respiratory failure and that for VAP. The entry describes at the basic level the identification, description, and treatment for the organism. The treatment section does state the success of colistin for treatment, it but no external reference is provided for independent verification. One section of the entry is marked as needing considerable re-write. Two of the references listed link to PubMed.

Chronic Liver Failure w/ Hepatic Encephalopathy – The entry for Liver Failure is two paragraphs long, with four references provided. It clearly lacks the needed information in context to the clinical question. Not categorized as a stub, but perhaps is should be?

Typing in “chronic liver failure” leads the user to the “Liver Failure” entry discussed above; there is also a separate entry for hepatic encephalopathy. The HE entry fares somewhat better in a quick evaluation than some of the other entries - this entry is accurate in its description of the condition; however, only pathogenesis, grading and treatment are briefly covered. The latest substantive edit was in February 2006 to correct a statement on the effectiveness of lactulose, and a reference is provided. However, the very next paragraph indicates the decline of the use of Neomycin, with no external references to support the statement.

Bronchoscopy - - the importance of the bronchoscopy for this case is essentially to understand the basics of the procedure if unfamiliar, and this entry meets that need. While the entry is not lengthy, it is of sufficient details to understand the aspects involved – including a link to an image from a public-domain website. And look! The references include a link to MedlinePlus articles.

Preliminary conclusions: Even this brief snapshot of Wikipedia has utility for understanding the issues involved in a resource that allows anyone to edit the content. These issues are commonly heard when the topic of Wikipedia arises, and in the particular context of medicine - unsupported statements, widely varying level of detail, and problems with clinical relevance or direct applicability to clinical questions, such as the one explored by this case, will need to be carefully considered.

Your thoughts?

Additional general commentary on Wikipedia:
- "The Faith Based Encyclopedia," written by a former Brittanica editor-in-chief

- "Internet Encyclopedias Go Head to Head," from Nature; this has been disputed and fairly widely discussed online

- "Can Wikipedia conquer expertise?," from the New Yorker

Wikipedia for Drug Information

Several posts on this blog have looked at the varying ways Wikipedia can be used for addressing medical concepts.  Reuters Health reports today on a study from researchers at Nova Southeastern University that compares the scope, completeness, and accuracy of drug information in Wikipedia when comparted to Medscape Drug Reference (MDR). 

Using assessments in 8 categories of drug information, the study authors report that Wikipedia answered fewer drug questions than MDR (40% vs. 82.5%, p<0.001) see PubMed abstract.

Interesting article.  Did you know to date there are over 30 articles in Pubmed referencing Wikipedia? More than 50 mention wikis in general? 

What is a prodrug?

The Wikipedia entry on colistin notes that colistimethate is an "inactive prodrug of colistin" - this portion of the entry seems to be directly related to this laboratory study by Bergen et al. published in the June 2006 issue of Antimicrobial Agents and Chemotherapy, which reports to be the first study establishing that colistimethate is a prodrug, though this article is not cited in the Wikipedia entry.

Bartleby.com defines "prodrug" as an "inactive precursor of a drug, converted into its active form in the body by normal metabolic processes" (there's also a brief Wikipedia entry on prodrugs) -- the classification of colistimethate as a prodrug by Bergen et al. implies that colistimethate on its own is inactive, but is converted (i.e. metabolized) to colistin after injected into the human body.

This may have significant implications for susceptibility testing - exposing cultured bacteria to colistimethate may provide incorrect estimates of the antibiotic's activity against the bacteria, as conversion within the body to the active form via hydrolysis may be required (Bergen et al. recommend that colistin should be used for these kinds of assays).

As you review the studies published in the literature, this consideration may help you with assessing and critiquing the microbiological assays employed in the studies, as well as any pharmacokinetic and pharmacodynamic investigations. This information would also be key if the initial question about colistin prompted additional follow-up questions such as "How well do microbiological assays perform with respect to colistin sensitivity?" or "How do we determine if we're administering 'enough' colistin to the patient?"

Related link:
The article by Bergen et al. mentions the "Bad Bugs, No Drugs" campaign launched by the Infectious Diseases Society of America, subtitled "As Antibiotic Discovery Stagnates . . . A Public Health Crisis Brews." The campaign includes a white paper, press materials, description of sponsored legislation, and key statistics on the growing problem of antimicrobial resistance among some bacterial strains.

Background Resources for October 2006 Case

Table 1 of our current case lists several medical concepts which are central to our clinical question. This post is intended to explain why each concept is important, how to assess the quality and relevance of background information sources, and to provide links to freely available resources may be useful for acquiring background knowledge on these topics. You may also wish to consult textbooks, databases, or other subscription items available at your own library.
The Question:
What is the evidence basis for the use of intravenous colistin for multi-drug resistant Acinetobacter infections in the adult, non-neutropenic, critical care population?

How to Evaluate Online Resources:

Medical Library Association: A User's Guide to Finding and Evaluating Health Information on the Web

MedlinePlus: Guide to Healthy Web Surfing

National Center for Complementary and Alternative Medicine: 10 Things To Know About Evaluating Medical Resources on the Web

National Cancer Institute: How To Evaluate Health Information on the Internet: Questions and Answers

U.S. Food and Drug Administration: How to Evaluate Health Information on the Internet

The Concepts:
Respiratory Failure
The patient was admitted to the ICU with respiratory failure; this informs you that the patient is currently unable to breathe on his own, resulting in the use of mechanical ventilation and leading to the development of ventilator-associated pneumonia (VAP).

eMedicine: Respiratory Failure

The Merck Manuals Online Medical Library, Home Edition: Respiratory Failure

MeSH Database: Respiratory Insufficiency

Ventilator-Associated Pneumonia
The patient is showing signs of VAP, which is why the cultures (brochoscopy and bronchoalveolar lavage) were conducted, leading to the identification of the Acinetobacter species in this patient.

CDC: Ventilator-Associated Pneumonia

MeSH Database: Pneumonia, Bacterial; Respiration, Artificial; Ventilators, Mechanical

Acinetobacter
This is the organism identified as causing the patient's pneumonia, and you've been asked to find evidence on drugs to treat this specific type of infection.

CDC: Drug Resistant Acinetobacter Infections in Healthcare Settings

eMedicine: Acinetobacter

MeSH Database: Acinetobacter

Chronic Liver Failure with Hepatic Encephalopathy
This is the other condition (in addition to respiratory failure) for which the patient was admitted to the ICU. It may or may not turn out to have an impact on the drug regimen the patient receives, but helps you understand the overall clinical picture for this patient. Hepatic encephalopathy is the underlying cause of the patient's respiratory failure, as it leads to decreased mental status which in turn causes respiratory dysfunction and the inability of the patient to protect his own airway. The resources listed below address hepatic encephalopathy, but we don't know the cause or type of the chronic liver failure.

MedlinePlus Medical Encyclopedia: Hepatic encephalopathy

eMedicine: Encephalopathy, Hepatic

MeSH Database: Hepatic Encephalopathy; Liver Failure

Bronchoscopy
The patient underwent bronchoscopy when signs of VAP developed. Bronchoscopy is a fairly common procedure, so it will help you in the future to understand this term.

MedlinePlus Medical Encyclopedia: Bronchoscopy

UpToDate Patient Information: Fiberoptic Bronchoscopy

MeSH Database: Bronchoscopy

Bronchoalveolar Lavage
The procedure is used with bronchoscopy to identify the infectious organism affecting a patient. "Lavage" essentially means "to wash," and has its origin in the Latin lavare - the lungs are washed with fluid, which is then suctioned back up for culturing and diagnostic purposes.

MeSH Database: Bronchoalveolar Lavage

Wikipedia: Bronchoalveolar Lavage - Normally, you might want to consult other, more authoritative background resources before checking Wikipedia, but there is very little basic information on this procedure online. In this case, reading the Wikipedia entry can give you a basic idea of what bronchoalveolar lavage consists of.

Antibiotic Sensitivity/Susceptibility Testing
This type of testing is used to determine which agents will be effective against an infectious organism. It is how doctors know what the "right" antibiotic is to use for an infection.

Lab Tests Online: Susceptibility Testing

MeSH Database: Microbial Sensitivity Tests

Colistin
Colistin is an antimicrobial (or antibacterial) drug, and the clinicians would like to know if it has been proven effective against Acinetobacter infection. A search of free resources does not turn up much of anything on this drug. However, through further investigation, we find that Colistimethate is a derivative of Colistin, and information is available on that.

MeSH Database: Colistin

MedlinePlus Drug Information: Colistimethate Injection

Have other suggestions for background resources? Post them in the comments.

Using the MeSH Browser as a dictionary

Sandra of Discovering Biology in a Digital World provides a great discussion of the MeSH Browser, "MeSH part I. Where can you find the meaning of "life"?"

Noting that you can't often get a "quick" definition for a scientific term straight from a scientist, she also points out that the authority and precision of definitions provided by Google or Wikipedia may not be reliable enough for understanding the basics of a particular scientific word or phrase.

Sandra then gives a nice overview of how to find definitions using the scope notes available via NCBI's MeSH database.

It's so easy to focus on MeSH as a means to an end, a way to find the "right" terms to find good articles in PubMed on a topic, but Sandra's post reminded me that the MeSH database can serve as a reference resource all on its own.

In addition to using the scope notes to understand a term's meaning, a few other "uses" that come to mind:
- using the tree structures to begin to understand which body systems are affected by a given disease and how different conditions are related to each other
- looking at the entry terms to figure out common synonyms for a subject heading
- using the spell check/suggestion feature to "decode" a medical word (drug, disease, etc) that I've heard but never seen in print, or that's I just find difficult to spell correctly

For those interested in more on the history and functions of MeSH, including another version of the MeSH browser, check out the NLM's MeSH page.

Vancomycin

There's a really thorough discussion of the history of vancomycin and how its use has evolved in the 50+ years it has been available in the US in this 2006 article:
Levine DP. Vancomycin: a history. Clin Infect Dis. 2006 Jan 1;42 Suppl 1:S5-12.

The Wikipedia entry on this antibiotic also gives a little history and briefly discusses vancomycin resistance. For a better examination of vancomycin resistance, consider this CDC page on vancomycin-resistant Enterococcus and this one on vancomycin-resistant Staphylococcus.