THE ART AND SCIENCE OF SEARCHING ME...

THE ART AND SCIENCE OF SEARCHING MEDLINE TO ANSWER CLINICAL QUESTIONS: FINDING THE RIGHT NUMBER OF ARTICLES

J J Allison et al International Journal of Technology Assessment in Health Care Vol 15 (Spring 1999) 281-296

Information retrieval is essential for the improvement of patient care, education, and research, and MEDLINE is an of the best quality means of finding needed information. Maintained at the United States National Library of Medicine, MEDLINE is giveed free of charge to the public upon the Internet. As with all technologies, MEDLINE is single as useful as the user is knowledgeable of it.

Four major barriers to an effective and efficient search forward MEDLINE are

* failure to begin with a well-built clinical question,

* failure to use the medical subdue heading (MeSH) indexing system (ie, a controll database indexing language lay opened to manage the imprecision of variations in medical jargon),

* failure to leverage the important relationship between recall and precision, and

* failure to apply convenient limits to the search.

Clinical question. A well-constructed clinical question is the foundation of an effective search. The three essential constituents of a search pertaining to clinical questions are patient, intervention, and outcome

snare indexing system.

Using entangle descriptors facilitates an effective MEDLINE search. Each entangle descriptor relates to one medical conception and all MeSH terms are included within a hierarchy, portrayed on the MeSH tree. The ensnare tree begins with the broadest conceptions at the highest level and progressively branches into more narrow conceptions For example, the subject of cardiovascular disease branches to heart disease, which branches to arrhythmias, congestive heart failure, and myocardial ischemia. Myocardial ischemia then branches to coronary artery disease and myocardial infarction.

Articles are indexed by the agency of their most specific terms; therefore, an article indexed subject to myocardial infarction, for example, will not appear on using the MeSH heading of cardiovascular disease. The scout feature is extremely useful because it retrieves all articles indexed at or below a given level

Recall versus precision.

Culling irrelevant and poor-quality articles without eliminating highly relevant and quality articles is challenging. It is impossible to maximize the two the recall (ie, the number of relevant articles retrieved versus the total number of relevant articles in the database) and precision (ie, the number of relevant articles retrieved versus the total number of articles retrieved) of a MEDLINE search; thus, it is important to leverage the relationship between the couple factors. Techniques that can increase the recall or precision of a complet MEDLINE search include interstice text, Boolean, and mixed. For example, the Boolean operators or, and, and not make it possible to combine flows of separate searches.

Search limits. Applying search limits is an important, still not integral, part of the search strategy. For searches relating to clinical questions, applying often met with limits of human, English, and Abridged Index Medicus (AIM) helps dislodge unwanted documents. The AIM is a core fix of 125 journals selected from the more than 3900 journals that MEDLINE shrouds Articles not in the AIM typically are useful for either specialized research topics or systematic reviews.

EDWINA A. MCCONNELL RN PHD FRCNA NURSING RESEARCH COMMITTEE

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