MEDLINE: the options for health professionals.

The bibliographic database MEDLINE, produced by the National Library of Medicine (NLM), is a computerized index to the world's biomedical literature. The database can be searched back to 1966 and contains 6.8 million records. The various means of access are divided, for the purposes of this article, into three categories: logging onto a remote host computer by telephone and modem or by the Internet; subscribing to part or all of the database on compact disc (CD-ROM); and leasing the data on a transport medium such as magnetic tape or CDs for loading on a local host computer. Decisions about which method is preferable in a given situation depend on cost, availability of hardware and software, local expertise, and the size of the intended user population. Trends include increased access to the Internet by health professionals, increased network speed, links from MEDLINE records to full-text databases or online journals, and integration of MEDLINE into wider health information systems.