Background

Several steps must take place before a hospitalized patient receives a medication ordered by a clinician:

• Ordering: the clinician must select the appropriate medication and the dose and frequency at which it is to be administered
• Transcribing: the clerk must read the order correctly and communicate it accurately to the pharmacist
• Dispensing: the pharmacist must check for drug–drug interactions and allergies, then release the appropriate quantity of the medication in the correct form
• Administration: the nurse must receive the medication and supply it to the correct patient

A classic study of inpatient medication errors found that approximately 90% occurred at either the ordering or transcribing stage. These errors can be due to a variety of causes, including poor handwriting, ambiguous abbreviations, or simple lack of knowledge on the part of the ordering clinician.

Computerized provider order entry (CPOE) refers to any system in which clinicians directly enter medication orders (and, increasingly, tests and procedures) into a computer system, which then transmits the order directly to the pharmacy. These systems have become increasingly common in the inpatient setting as a strategy to reduce medication errors. A CPOE system, at a minimum, ensures standardized, legible, and complete orders and thus has the potential to greatly reduce errors at the ordering and transcribing stages.

CPOE systems are generally paired with some type of Clinical Decision Support System (CDSS). A typical CDSS suggests default values for drug doses, routes of administration, or frequency and may offer more sophisticated drug safety features such as checking for drug allergies or drug–drug or even drug–laboratory (eg, warning a clinician before ordering a nephrotoxic medication in a patient with elevated creatinine) interactions. At the highest level of sophistication, CDSS prevents not only errors of commission (eg, ordering a drug in excessive doses or in the setting of a serious allergy), but also of omission. (For example, an alert may appear such as, "You have ordered vancomycin; would you like to order serum vancomycin level after the third dose?" or, even more sophisticated: "The admitting diagnosis is hip fracture; would you like to order enoxaparin for DVT prophylaxis?")
 


Source: Grizzle AJ, Mahmood MH, Ko Y, et al. Reasons provided by prescribers when overriding drug-drug interaction alerts. Am J Manag Care. 2007;13:573-578. [go to PubMed]

Evidence of Effectiveness

In theory, CPOE offers numerous advantages over traditional paper-based order-writing systems. Examples of these advantages include averting problems with handwriting, similar drug names, drug interactions, and specification errors; integration with electronic medical records, decision support systems, and adverse drug event reporting systems; faster transmission to the pharmacy; and potential economic savings.

These proposed benefits have been empirically confirmed to some extent, and recent studies have added to the evidence base supporting CPOE. Initial studies of CPOE systems were generally single-institution studies using "home-grown" systems; these studies did demonstrate significant reductions in adverse drug events. A recent review found reductions in medication errors, but the effect on clinical outcomes was unclear. Indirect support for the clinical benefits of CPOE was provided by a study in which CPOE implementation was associated with reduced mortality and complication rates.

However, high rates of adverse drug events persist in some hospitals with entirely computerized order entry systems. One interpretation of these results is that decision support is the key intervention in reducing errors, and that CPOE by itself may have a relatively limited effect in reducing harm from medication errors. Also, a significant proportion of medication errors occur at the dispensing and administration stages, and these errors will not be prevented by CPOE (here, promising error reduction strategies include the involvement of unit-based pharmacists and the use of bar code medication administration systems).

Implementation Issues

Early implementation of CPOE was associated with unexpected adverse consequences in some instances: in one widely cited study, implementation of a commercially available CPOE system was associated with an increased mortality rate in a pediatric intensive care unit (ICU). Study authors hypothesized that workflow disruptions caused by CPOE, such as inability to obtain medications quickly in emergencies and reduction in the time clinicians spent at the bedside, may have contributed to the adverse clinical outcomes. Subsequent studies have characterized a variety of unintended consequences of CPOE (Table).

Table. Types of Unintended Consequences of Computerized Provider Order Entry Systems

More or new work for clinicians

Unfavorable workflow issues

Never-ending system demands

Problems related to persistence of paper orders

Unfavorable changes in communication patterns and practices

Negative feelings toward the new technology

Generation of new types of errors

Unexpected changes in an institution's power structure, organizational culture, or professional roles

Overdependence on the technology

(Reprinted with permission from Elsevier. In: Campbell EM, Sittig DF, Ash JS, Guappone KP, Dykstra RH. Types of unintended consequences related to computerized provider order entry. J Am Med Inform Assoc. 2006;13:547-556.)

These factors contributed to the high-profile failure of an expensive computerized order entry system. However, as institutions gain experience with CPOE implementation, greater awareness of the potential unintended consequences of this technology will likely avoid these problems. For example, a subsequent study documented successful implementation of the same CPOE system that had been associated with increased pediatric ICU mortality. The authors of the second study carefully planned the implementation process, in collaboration with the early system users, to minimize workflow disruptions and maximize the system's ease of use.

Current Context

CPOE is recommended by the Agency for Healthcare Research and Quality and the National Quality Forum as one of the 30 "Safe Practices for Better Healthcare." The Leapfrog Group also recommended CPOE implementation as one of its first three recommended "leaps" for improving patient safety.

Despite these strong recommendations, hospitals have been slow to implement CPOE. A 2009 study found that only 17% of US hospitals had implemented a CPOE system, and the proportion of outpatient practices using CPOE is even smaller. Cost is likely a factor, as are resistance to change at the organizational and individual provider level and a lack of systems that have been implemented successfully in a variety of clinical settings.