How to Access the PDQ System A doctor can access the PDQ database directly. To do so, the doctor needs a computer equipped with a modem and telecommunications software, a CD-ROM reader or access to the Internet, a web of computer networks that reaches all over the world.
A modem and telecommunications software enable the user's computer to link up with the central computer that contains the PDQ system at the National Library of Medicine (NLM) or a commercial vendor over a standard telephone line. A CD-ROM reader lets the user's computer read PDQ information from an optical disk plugged into the computer. If a doctor's computer is linked to the Internet, he or she can also access the PDQ system through the NLM or other commercial database distributors. Although not essential, it is also highly desirable to have a printer so that a copy of the PDQ data appearing on the screen can be produced for the doctor and patient to review.
Online Access through the National Library of Medicine (NLM) PDQ is available on the National Library of Medicine's computer network. This system, which is called MEDLARS—Medical Literature Analysis and Retrieval System—is available 24 hours a day, seven days a week to doctors with computers that communicate with the NLM system. Medical or hospital libraries that have access to databases on the MEDLARS system have access to PDQ. PDQ is particularly easy to use as implemented on the NLM MEDLARS system because it can be searched by making selections from a menu of choices.
