Computerized Physician Order Entry: Has the Time Come?

Jacob Reider, MD


Medscape General Medicine. 2003;5(2) 

In This Article


In its landmark reports on quality of medical care,[1,2] the Institute of Medicine brought attention to the frequency of errors in medicine, and offered several clear suggestions for how we might enhance the safety and efficacy of the care that we provide. A key component of many such proposals is Computerized Physician Order Entry (CPOE).

CPOE is software that permits physicians to enter their hospital or outpatient orders directly into a computer system. Broadly defined, implementations of CPOE will vary from very simple systems, such as PDA-based prescription writing software, to fully integrated electronic medical records systems. Still, most CPOE implementations are hospital-based, and involve several core components: hospital demographic and registration systems, departmental information systems, billing systems, and/or integrated clinical information systems.

Most hospitals have some or all of these legacy systems installed. They are connected to each other so that data can pass between them according to defined rules (Figure). For example, a laboratory system may receive an order for a CBC, generate a "work order" for the phlebotomist to draw the blood, receive the CBC result from the laboratory device, and send this result to a clinical information system where the result is reviewed by the ordering physician. In addition, a message can be sent to the billing system to automatically generate a bill for the CBC.

Example of a hospital information system composed of several specialized systems interfaced with each other. These systems share registration and demographic information with one central registration system. Satellite systems, such as radiology, labs, pharmacy, and cardiology, receive demographics, and return clinical information for viewing by clinical staff.

While the complexity of these systems can be significant, the framework in most settings is the same: Patient information is moved from department to department. Data is entered either manually (by a registration clerk upon admission, or by a floor clerk when physicians' paper orders are transcribed) or electronically through an interface to a laboratory device, a medical transcription system, or an EKG machine. Patient information typically moves in the following ways:

Hospital information system. The hospital information system maintains clinical and demographic information about the patients in the hospital. Very often, this system forms the "hub" of a wheel comprising many separate computer systems within a hospital. These computer systems are connected through interfaces, so that data are passed between systems. Very often, these systems are based on a registration and demographic database.

Departmental information systems. Laboratory, radiology, and pharmacy information systems are components of most hospital technology infrastructures. These systems are designed to support the processing, entry, and reporting needs of the departments in which they are employed. For example, a pharmacy system may need detailed medication interaction information so that the pharmacist would be alerted if 2 incompatible medications were prescribed. However, a radiology system would have no such functionality, but would have software to help a radiology department manage the ordering, billing, and reporting functions of performing a CT scan. Finally, a laboratory information system would perform functions that assist laboratory staff in the entry of orders and in the collection of the laboratory results, either from manual entries by staff members or from automated interfaces with laboratory devices.

User interface software. Many hospitals now have computer systems that enable physicians to retrieve laboratory data or radiology results on a computer. These are primarily data-retrieval tasks.

While the physician's interaction with a legacy system is usually one of data retrieval, CPOE requires that physicians begin to enter information into the computer. Physician data entry is the primary reason that CPOE provides so much potential for quality improvements in healthcare, yet it is also the primary reason that CPOE is so challenging to implement.