Moving beyond MEDLINE
© 1998 Canadian Medical Association
CMA members who register for the CMA's free OSLER (OVID Search: Link to Electronic Resources) service obtain unlimited access to MEDLINE, AIDSLINE, CancerLit and HealthSTAR. Most of our registrants search MEDLINE exclusively, but it is worth considering the scope, content and coverage of the other databases, especially if a truly comprehensive search is the goal. Each database is unique and contains many documents that cannot be found in MEDLINE.
MEDLINE, produced by the National Library of Medicine in the US, contains close to 9 million bibliographic citations and abstracts indexed from more than 4000 biomedical journals, as well as selected monographs from congresses and symposia. Coverage begins in 1966 and includes medicine, allied health, the biological, clinical and physical sciences, dentistry, nursing, veterinary medicine, communication disorders, epidemiology and reproductive biology.
AIDSLINE offers citations focused on research, clinical management, epidemiology and health policy concerning AIDS. Thousands of international journals, government reports, letters, technical reports, meeting abstracts, monographs, theses, newspaper articles and audiovisual materials are indexed. Coverage begins in 1980.
All about cancer
CancerLit is produced by the US National Cancer Institute and offers citations concerning all aspects of cancer therapy, cancer-causing agents, immunology and the physiology of cancer. As well as citations from 200 core journals, it contains references to government reports, theses, selected monographs and abstracts of papers presented at professional meetings. Its coverage begins in 1983.
HealthSTAR contains references to health services technology, administration, economics, policy and research. The database is produced by the National Library of Medicine and the American Hospital Association, and more than 3 million records such as journal articles, monographs, book chapters, government documents and meeting abstracts can be searched. Its coverage begins in 1975.
The best way to illustrate differences between the databases is to conduct searches and compare results. OVID allows users to search each of the databases without having to type the strategy every time. Start with the most current segment of MEDLINE (1995-1998), and look for articles on the history of AIDS. Type AIDS, choose Focus to retrieve articles in which that subject is the major theme, then apply the subheading History. Limit the results further by restricting to Human and English language. A set of 15 references will be retrieved. Click on Change Databases in the OVID Toolbar and go to CancerLit. When asked whether to rerun the search in the new database, click Yes. The system immediately performs the same search for information about the epidemic s history, but automatically limits the search to references outside of MEDLINE, eliminating duplication. No citations on the history of AIDS are found in CancerLit, but in both AIDSLINE and HealthSTAR 5 additional references are retrieved.
Because types of publications searched vary among the databases, running a search against each one is the only way to ensure that a full search of all possible information has been completed. The option to limit a search to "non-MEDLINE" is available in all databases except MEDLINE itself. If a MEDLINE search has already been done and you wish to try it in another database, type in the relevant subject heading and click "nonmedline" on the Main Search Page before hitting Perform Search.
OVID Tip of the Month
There are many short-cuts and time-savers within the OVID search software that users pick up. To move directly to articles with your topic as the major theme or focus, insert an asterisk before the search term. If you try to replicate the series of searches for the history of the AIDS epidemic, you ll notice that the asterisk appears in the search history box before every term for which you applied Focus. If you want to reach the list of Subheadings applicable to your subject heading quickly, type sh AIDS into the Keyword box. All the subheadings appear and beside each one is a bracketed number indicating the quantity of references indexed to articles with that subheading. You can then select one or several subheadings and retrieve the citations.
Visit OSLER at www.cma.ca/osler. For assistance with online registration, call 800 457-4205. For help with online searching strategies, call 800 663-7336 x2255 to reach the OSLER Support Librarian. Emailed questions may be sent to email@example.com. Deidre Green, OSLER support librarian