The highly structured nature of MEDLINE means it is possible to conduct highly sophisticated and targeted searches;
It is the largest database of it's kind in the world;
Coverage of a large number of journals, back to 1966.
Limitations of MEDLINE
MEDLINE is not a full text database - it contains structured information about journal articles, not the articles themselves;
There is a significant US bias - over 50% of material is from American journals;
Not all of the content of each journal is included - for example letters, or editorial material may not meet the criteria for inclusion. In addition journals with a wide scope such as Nature will only have those articles with a medical focus selected by MEDLINE;
Only journal articles are included; not books, book chapters, conference proceedings, statistical tables, or official documents;
There is some delay in receiving each month's data from the USA. For the most recent information it is necessary to consult PubMed, which is updated daily. Bear in mind the recent records (PreMEDLINE) will not have had subject headings added;
Some articles will be misclassified, so for a comprehensive search it is always necessary to include a wide range of possible terms.
