With the proliferation of websites offering some form of MEDLINE searching, the Health Sciences Libraries have developed this resource to help users understand the options and limitations of the several systems available to them.

• What is MEDLINE?
• What is MEDLINE In-Process & Other Non-Indexed Citations?
• OVID and PubMed
• MEDLINE Comparison Chart

What is MEDLINE?

MEDLINE is a biomedical bibliographic database that was developed by the National Center for Biotechnology Information (NCBI) at the National Library of Medicine (NLM), located at the National Institutes of Health (NIH). MEDLINE currently indexes over 50 years of articles from more than 5000 journals. It contains citations to over 16 million articles, and is adding new articles at a rate of nearly a million articles a year. MEDLINE covers basic biomedical research and the clinical sciences, including nursing, dentistry, veterinary medicine, pharmacy, allied health, and pre-clinical services. Some aspects of biology, marine biology, chemistry, biophysics, and plant and animal science are also covered in MEDLINE. MEDLINE does not contain any full-text articles, but many of the systems that search MEDLINE include access to full text journals.

What is MEDLINE In-Process & Other Non-Indexed Citations?

The purpose of MEDLINE In-Process & Other Non-Indexed Citations is to provide quick access to recently published articles before they can be fully indexed and included in MEDLINE. Only the citation and abstract, if available, are searchable in MEDLINE In-Process. Once subject headings and other relevant data are added, the article's complete record is incorporated into the full MEDLINE database and removed from MEDLINE In-Process.

OVID and PubMed

OVID and PubMed are systems that search the MEDLINE database; each has advantages and disadvantages. PubMed is a government-sponsored system and is freely accessible by anyone who can access the Internet; it provides limited free access to full-text journals in addition to providing links to electronic items owned by the Drexel University Libraries when accessing PubMed via the links from the library web pages. OVID is a privately-owned interface developed by OVID Technologies. OVID's primary advantage is that the user can search different databases in several disciplines using the same interface; use is restricted to Drexel University students, staff and faculty and Hahnemann and St. Christopher's Hospital residents. Access to OVID from off-campus requires users to identify themselves in order to confirm their affiliation with the university ("Off-Campus Access" ). PubMed is generally easier to search than OVID, but it can return large numbers of irrelevant articles unless the user is familiar with the advanced search techniques of the system. OVID can be more difficult to learn, but complex and precise searching is easier to do on OVID than on PubMed. It allows a greater level of control over a search which can result in retrieval of fewer irrelevant articles.

The chart below lists some of the specific features of each system:

University faculty, staff, and students can contact reference assistance librarians at the Health Sciences Libraries or Hagerty Library for additional information about MEDLINE, other databases, and the many information and education services available through the Libraries.