P.Mean >> Category >> Information searching (created 2005-01-19).

These pages describe efficient strategies for finding information in peer-reviewed journals or on the Internet. Also see Category: Publication bias and Category: Systematic overviews. Articles are arranged by date with the most recent entries at the top. You can find outside resources at the bottom of this page.


19. What percentage of medical care is evidence based? (January/February 2012) and P.Mean: Percentage of care that does not have a medical basis (created 2012-02-06) At a meeting I was attending, a statistic came up that has a controversial heritage "at least 50% of medical care has no valid scientific basis." The number cited is not always 50%, but it is almost always a number that is low enough to be alarming. Here are some resources on the basis of this statistic.


18. The Monthly Mean: The dark side of search engine optimization (July/August 2011)

Outside resources:

Babelfish Translation Description: This website will provide translations to/from Chinese, English, French, German, Italian, Japanese, Korean, Portuguese, Russian, Spanish. The translations are not always perfect, but it is invaluable when you stumble across an interesting website in a language you don't understand.

How do we assess the quality of information? Description: This website provides a checklist of questions that you can use to assess the quality of web pages that provide health information.

Greenhalgh T, Peacock R. Effectiveness and efficiency of search methods in systematic reviews of complex evidence: audit of primary sources. BMJ. 2005;331(7524):1064-1065. Excerpt: In systematic reviews of complex and heterogeneous evidence (such as those undertaken for management and policymaking questions) formal protocol-driven search strategies may fail to identify important evidence. Informal approaches such as browsing, "asking around," and being alert to serendipitous discovery can substantially increase the yield and efficiency of search efforts. "Snowball" methods such as pursuing references of references and electronic citation tracking are especially powerful for identifying high quality sources in obscure locations. [Accessed October 29, 2009] Available at: http://www.bmj.com/cgi/content/abstract/331/7524/1064.

Michael Simon, Elke Hausner, Susan Klaus, Nancy Dunton. Identifying nurse staffing research in Medline: development and testing of empirically derived search strategies with the PubMed interface. BMC Medical Research Methodology. 2010;10(1):76. Abstract: "BACKGROUND: The identification of health services research in databases such as PubMed/Medline is a cumbersome task. This task becomes even more difficult if the field of interest involves the use of diverse methods and data sources, as is the case with nurse staffing research. This type of research investigates the association between nurse staffing parameters and nursing and patient outcomes. A comprehensively developed search strategy may help identify nurse staffing research in PubMed/Medline. METHODS: A set of relevant references in PubMed/Medline was identified by means of three systematic reviews. This development set was used to detect candidate free-text and MeSH terms. The frequency of these terms was compared to a random sample from PubMed/Medline in order to identify terms specific to nurse staffing research, which were then used to develop a sensitive, precise and balanced search strategy. To determine their precision, the newly developed search strategies were tested against a) the pool of relevant references extracted from the systematic reviews, b) a reference set identified from an electronic journal screening, and c) a sample from PubMed/Medline. Finally, all newly developed strategies were compared to PubMed's Health Services Research Queries (PubMed's HSR Queries). RESULTS: The sensitivities of the newly developed search strategies were almost 100% in all of the three test sets applied; precision ranged from 6.1% to 32.0%. PubMed's HSR queries were less sensitive (83.3% to 88.2%) than the new search strategies. Only minor differences in precision were found (5.0% to 32.0%). CONCLUSIONS: As with other literature on health services research, nurse staffing studies are difficult to identify in PubMed/Medline. Depending on the purpose of the search, researchers can choose between high sensitivity and retrieval of a large number of references or high precision, i.e. and an increased risk of missing relevant references, respectively. More standardized terminology (e.g. by consistent use of the term "nurse staffing") could improve the precision of future searches in this field. Empirically selected search terms can help to develop effective search strategies. The high consistency between all test sets confirmed the validity of our approach." [Accessed October 25, 2010]. Available at: http://www.biomedcentral.com/1471-2288/10/76.

Moerman C, Deurenberg R, Haafkens J. Locating sex-specific evidence on clinical questions in MEDLINE: a search filter for use on OvidSPTM. BMC Medical Research Methodology. 2009;9(1):25. Available at: www.biomedcentral.com/1471-2288/9/25 [Accessed April 16, 2009]. Abstract: Background Many recently published clinical studies report sex-specific data. This information may help to improve clinical decision-making for both sexes, but it is not easily accessible in MEDLINE. The aim of this project was to develop and validate a search filter that would facilitate the retrieval of studies reporting high quality sex-specific data on clinical questions. Methods A filter was developed by screening titles, abstracts and Medical Subject Headings (MeSH) in a set of 80 high quality and relevant papers, 75 of which were identified through a review of clinical guidelines and five through other means. The filter, for use on OvidSPTM, consists of nine command lines for searching free text words in the title, abstract and MeSH of a paper. It was able to identify 74/80 (92.5%) of the articles from which it was derived. The filter was evaluated in a set of 622 recently published original studies on Alzheimer's disease and on asthma. It was validated against a reference of 98 studies from this set, which provided high quality, clinically relevant, sex-specific evidence. Recall and precision were used as performance measures. Results The filter demonstrated 81/98 (83%) recall and 81/125 (65%) precision in retrieving relevant articles on Alzheimer's disease and on asthma. In comparison, only 30/98 (31%) recall would have been achieved if sex-specific MeSH terms only had been used. Conclusion This sex-specific search filter performs well in retrieving relevant papers, while its precision rate is good. It performs better than a search with sex-specific MeSH. The filter can be useful to anyone seeking sex-specific clinical evidence (e.g., guideline organizations, researchers, medical educators, clinicians).

Straus S, Haynes RB. Managing evidence-based knowledge: the need for reliable, relevant and readable resources. CMAJ. 2009;180(9):942-945. Excerpt: One method for finding useful evidence is the "5S approach". This framework provides a model for the organization of evidence-based information services. Ideally, resources become more reliable, relevant and readable as one moves up the pyramid. To optimize search efficiency, it is best to start at the top of the pyramid and work down when trying to answer a clinical question. Available at: http://www.cmaj.ca/cgi/content/full/180/9/942 [Accessed September 9, 2009].

Scirus - for scientific information. Elsevier Science. Accessed on 2003-01-29. "Scirus is the most comprehensive science-specific search engine available on the Internet. Driven by the latest search engine technology, it enables scientists, students and anyone searching for scientific information to chart and pinpoint data, locate university sites and find reports and articles quickly and easily. It was launched by Elsevier Science, the leading international publisher of scientific information." www.scirus.com/

www.altavista.digital.com/ Alta Vista.

www.dogpile.com/ Dogpile

www.excite.com/ Excite

www.google.com Google

groups.google.com/googlegroups/deja_announcement.html Googol USENET archive.

www.hotbot.com/ HotBot

www.inference.com/ifind/ Inference Find

www.infoseek.com/ InfoSeek

www.lycos.com/ Lycos

www.metacrawler.com/ MetaCrawler

www.metafind.com/ Metafind

www.nlsearch.com/ Northern Light

www.webcrawler.com/ WebCrawler

www.yahoo.com/ Yahoo.

www.ohsu.edu/cliniweb Cliniweb.

www.medmatrix.org Medical Matrix.

omni.ac.uk  Omni.

omni.ac.uk/other-search/ Other search engines.

Creative Commons License All of the material above this paragraph is licensed under a Creative Commons Attribution 3.0 United States License. This page was written by Steve Simon and was last modified on 2010-04-11. The material below this paragraph links to my old website, StATS. Although I wrote all of the material listed below, my ex-employer, Children's Mercy Hospital, has claimed copyright ownership of this material. The brief excerpts shown here are included under the fair use provisions of U.S. Copyright laws.


17. Stats: Evidence Based Medicine for patients (April 23, 2008). There was an interesting email exchange on the email discussion group EVIDENCE-BASED-HEALTH@JISCMAIL.AC.UK. The first correspondent (TH) described a series of workshops that are intended to help patients access and evaluate health related websites.


16. Stats: Searching through the Current Index to Statistics (February 15, 2007). I wanted to search for any recent references about teaching Bayesian statistics. The American Statistical Association has a nice resource for its members, the Current Index to Statistics (CIS). I ran a search for bayes%+teach% in the Keyword/Title field and found 61 references. Notice that CIS uses the % symbol as a wildcard rather than the * symbol.

15. Stats: Advice for searching in PubMed (February 11, 2007). Trish Greenhalgh wrote a nice article about searching for medical information using PubMed. Here's a summary of the wonderful suggestions that she makes.


14. Stats: Medline is a very busy place (November 6, 2006). According to a National Library of Medicine announcement, www.nlm.nih.gov/pubs/techbull/so06/so06_med_35.html, Medline, a database that indexes millions of publications from thousands of medical journals, is celebrating its 35th anniversary.

13. Stats: Searching for pediatric articles on Medline (October 26, 2006). A recent publication Age-Specific Search Strategies for Medline. Monika Kastner, Nancy L Wilczynski, Cindy Walker-Dilks, Kathleen Ann McKibbon, Brian Haynes. J Med Internet Res 2006 (Oct 25); 8(4):e25 examines search strategies for articles relevant to geriatric medicine, adult medicine, pediatric medicine, neonatal medicine, and obstetrics. For studies of pediatric medicine, the most sensitive search used the following terms: child:.mp. OR adolescent.mp. OR infan:.mp. which had a sensitivity of 98% and a specificity of 81%.

12. Stats: Searching high level sources first (May 17, 2006). When you have to perform a search for the evidence, it pays to look at high level sources first. A recent discussion on the Evidence Based Health mailing list produced a nice list of these resources.

11. Stats: Recent developments in searching for evidence (January 31, 2006). Dean Giustini publishes a web log, the UBC Google Scholar Blog, that covers recent developments and improvements in searching for evidence, weblogs.elearning.ubc.ca/googlescholar/. While the title seems to limit the range of searching to the Google Scholar search engine (scholar.google.com/), the topics are actually quite varied and interesting.


10. Stats: Searching for information about the molasses with milk enema (October 15, 2005). I am part of an informal group at Children's Mercy Hospital that is trying to examine the process of Evidence Based Medicine to try to better understand it ourselves so that we can teach it and incorporate it into our practice. About a month ago, a question came up: In an otherwise healthy child with constipation what is the harm of giving a milk with molasses enema? I was just about to head out on a vacation, but I did a quick Google search and came up with some surprising references. But now that I have a bit more time, I thought it would be good to research the question carefully.

9. Stats: A third search for the evidence (August 2, 2005). Our evidence-based Medicine working group was asked to find evidence to answer the following question: In an otherwise healthy pediatric patient (> 1 month of age and < 5 years of age) which site (rectal, axillary, temporal) is most accurate in obtaining a core body temperature measurement? Here's the search strategy I used in PubMed.

8. Stats: Counterpoint on Google Scholar (July 19, 2005). A recently published article: Google Scholar: A source for clinicians? Henderson J. Cmaj 2005: 172(12); 1549-50 casts some doubt on the utility of Google Scholar as a resource for searching for medical information and describes some competing resources

7. Stats: Another search for evidence (June 7, 2005). Our new EBM discussion group is asking everyone to research the following question: In a patient (2 months 2 years of age) with a fever > 38.5 (rectal) at what CRP level should empiric antibiotic therapy be initiated? This question was later clarified to In an otherwise healthy pediatric patient between the ages of 2 months and 2 years) with a fever of 38.5 rectal or greater, at what level of CRP should one be concerned with a bacterial infection. Here's one possible search strategy.

6. Stats: More on searching the literature (May 17, 2005). I was trying to track down an article that I remembered from several years ago. It was an evaluation of smoking cessation programs for pregnant mothers to try to improve the birth outcomes, especially an increase in birthweight. This query could easily be fit into the PICO format: Does the use of smoking cessation programs (I) in women who are pregnant (P) lead to an improvement in birthweight (O) compared to simply offering advice and encouragement about the importance of quitting smoking (C)?

5. Stats: Searching the literature (May 3, 2005). Next week, our hospital will have a seminar on Reiki. I thought it would be useful to see what evidence there was on this technique.

4. Stats: PubMed tags (April 28, 2005). Searching in PubMed can be tricky. If you don't find what you want the first time, it may help to specify exactly what part of the PubMed record you want to search for.

3. Stats: Searching the Internet (April 26, 2005). A response to a question on the stat-l discussion group provided a clever way of searching the Internet. Someone asked about finding references about how to analyze ordinal data. There were several good responses, but there was one that I liked best.

2. Stats: Language resources (March 22, 2005). Once in a while, I will get an email or find a website written in a foreign language. The best way to handle this is through BabelFish.

1. Stats: The Digital Object Identifier (January 19, 2005). Many journals are now using the Digital Object Identifier (DOI) to reference their publications. The DOI was developed as an open standards group, the International DOI Foundation, as a stable way to identify digital files that might move over time. If you know the DOI, you should always be able to find the file.

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Creative Commons License This work is licensed under a Creative Commons Attribution 3.0 United States License. This page was written by Steve Simon and was last modified on 2010-04-11.