Medline: A Guide to Effective Searching in PubMed & Other Interfaces, 2nd Edition. By Brian S. Katcher, Pharm.D. San Francisco, Ashbury, 2006. Pages: 136. Price: $31.95.

How and where do I find the best available information on a biomedical topic? The “I” in this question may be a clinician, an educator, a basic science researcher, a trainee, or a patient, and the answer to this question is contingent on the questioner. A harried clinician does not want an encyclopedic review of a disease when seeking information about normal ranges for specific laboratory values, and the basic science researcher typically finds primary, rather than secondary review literature of greater interest. The answer is also context sensitive. The patient with an unusual symptom will seek information using the symptom, rather than disease class that might lead to this symptom, to formulate a search. After a clear diagnosis, the information sought shifts to a more encyclopedic search of the disease state, prognosis, and therapeutic options.

In his book, Dr. Katcher points out that variably focused and useful tools can now be deployed to search biomedical publications, including specialty journals; local institutional libraries, including database holdings such as Ovid; and, in the last decade, Web-based search tools, such as PubMed, Entrez, Google, Google Scholar, Scirus, and OAIster. Depending on the search engine used, searches may be directed toward rapidly proliferating unreviewed content in which author disclosure of conflicts of interest are the exception and/or toward peer-reviewed scientific content. Biomedical references electronically indexed by the National Library of Medicine currently comprise more than 15 million references, growing at an annual rate of nearly 600,000 references, exclusive of major pre-1966 indexing projects.

Criteria for medical information retrieval best practice include context-sensitive search result specificity and sensitivity, ease of search design, speed of retrieval, transportability of search results into reference-organizing software (e.g. , EndNote), and linkage to corresponding article content. This book primarily addresses the highly relevant topic of developing biomedical literature search strategies using the Web-based PubMed search engine and other interfaces. In this pleasantly readable and wisely concise book, the author provides the reader with the history, structure, and evolving nature of this remarkable indexed biomedical reference database and corresponding search engine. Readers will quickly come away with a clear sense of how to use indexing terms such as Medical Subject Headings (MeSH) to design searches that permit either refined, highly specific searches or broad, highly sensitive searches. The structured language reference indexing by National Library of Medicine indexers is the basis of subsequent retrieval using parallel index search terms in the MEDLINE search engines.

Eight of 10 Internet users have sought health information on-line, and the majority of referrals to one large publisher’s (HighWire) publications from Search Engines in 2005 came from Google (56%), with PubMed a distant second (8.7%). Dr. Katcher’s book alludes to this trend and makes the important point that expert level searches of high sensitivity and specificity constrained to peer-reviewed literature are currently unavailable using either Google or Google Scholar, due to the absence of indexing structure both in general Web content and in the search engine. The weighting given to search results in Google also has little to do with the quality of the publication. The natural language nature of search terms in Google is appealing and, as pointed out in the book, the recent introduction of the Unified Medical Language System by the National Library of Medicine now allows end users to submit natural language terms to PubMed, which then suggests or maps to appropriate MEDLINE indexing terms.

Appendix A in this book contains pointers to a number of Web-based resources available to the end-user and is alone worth the price of the book. The publisher, Ashbury Press, is maintaining pointers to the sites described in the appendix in an updateable manner ( The reviewers wish that this book was also made available for purchase as an electronic book with live pointers to pertinent and evolving Web content.

It is puzzling that despite a greater-than-ever need to serve as information managers and assessors, healthcare professionals typically receive no formal training in this critical area. This highly commendable book could and perhaps should serve as a key resource for designing a formal introduction to this topic in medical school, residency training programs, and refresher courses for those of us longer in the tooth. Although the book encourages a self-sufficient approach to literature searches, it is worth keeping in mind that most institutions with significant biomedical holdings have reference librarians with expertise in discerning the context of a search request and in developing a search strategy. It remains wise to check with one of these astute reference sleuths, when available, before concluding that one’s search strategy is fully optimized and uploading it into PubMed as an interval updated search.

Now if we could only figure out how to manage all the great references and Web-accessible content retrieved with these searches!

*Mayo Clinic College of Medicine, Rochester, Minnesota.