This link opens in a new window
Cochrane Collection Plus is the most comprehensive collection of databases from the Cochrane Library. Cochrane Collection Plus is an essential source of high quality health care data for providers, patients and those responsible for researching, teaching, funding and administrating at all levels of the medical profession. Cochrane Collection Plus combines the Cochrane Database of Systematic Reviews (CDSR), Cochrane Clinical Answers, Cochrane Central Register of Controlled Trials and Cochrane Methodology Register. Content: Mostly full-text (some full-text articles are through links). Publisher: Wiley & Sons, Ltd.
This link opens in a new window
PubMed is a version of MEDLINE which is available directly from the National Library of Medicine. Provides indexing for all areas of medicine including over 17 million citations from MEDLINE and other life science journals. Citations may include links to full-text content from PubMed Central and publisher web sites. Coverage: 1949 - present.
Here is a portion of the MeSH Tree structure for abdominal pain:
Diseases [C]
Pathological Conditions, Signs and Symptoms [C23]
Signs and Symptoms [C23.888]
Pain [C23.888.646]
Abdominal Pain [C23.888.646.100]
Abdomen, Acute [C23.888.646.100.200]
Colic [C23.888.646.100.600]
Renal Colic [C23.888.646.100.800]
What does this mean?A search of PubMed using the term "abdominal pain" will produce more relevant results than using the term "stomach ache."
Using the thesaurus or index terms, also called a controlled vocabulary, used by the database editors takes the guess work out of searching. Since we have many different ways of describing concepts, drawing all of these terms together under a single word or phrase in a database makes searching the database more efficient as it eliminates guess work.
Conducting a search in a database that uses controlled vocabulary or indexing terms is efficient and precise. The biggest advantage to controlled vocabulary is that once you do find the correct term, most of the information you need is grouped together in one place, saving you the time of having to search under all of the other synonyms for that term.
Click on the tutorial below for help creating better queries for PubMed.
MeSH, an abbreviation derived from Medical Subject Headings, is the National Library of Medicine's thesaurus of medical terms used to index articles from 5,400 of the world's leading biomedical journals for the MEDLINE®/PubMED® database. In MEDLINE/PubMed, every journal article is indexed with some 10-15 headings and subheadings.
The medical terms, called MeSH descriptors, are arranged in both an alphabetic and a hierarchical structure. The hierarchical structure is referred to as the MeSH Tree and is organized into 16 main categories, or branches.
The first branch of the MeSH tree is Anatomy under which appear subheadings Body regions, Musculoskeletal system, Digestive system, Respiratory system, etc. PubMed automatically searches the MeSH headings as well as the more specific terms beneath that heading in the MeSH hierarchy. This is known as the explosion feature.
Some terms occur in more than one place in the hierarchy. For example, "Eye" appears under the Anatomy branch, but also under the Sense Organs branch.