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Computerized Provider Order Entry
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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?")
Prescribers override more than half (53%) of CPOE generated alerts of critical drug-drug interactions (DDIs) without providing a reason. Of the 47% of alerts that were dismissed with clinical justification, 20% were rated as useful to pharmacists and 80% were rated as not useful.

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, which may have been attributable to workflow disruptions such as inability to obtain medications quickly in emergencies. Subsequent studies have characterized a variety of unintended consequences of CPOE (Table). These factors contributed to the high-profile failure of an expensive CPOE system. However, as institutions gain experience with CPOE implementation, greater awareness of the potential unintended consequences of this technology may help avoid these problems. Careful planning of the implementation process to minimize workflow disruptions and maximize the system's ease of use has been shown to avert adverse events relating to the new technology.

The integration of CDSS into CPOE systems also requires careful planning, and as yet, many aspects of optimal CDSS integration remain undefined. Decision support alerts can prevent harmful drug–drug interactions and promote use of evidence-based tests and treatments, but excessive and nonspecific warnings can lead to "alert fatigue"—whereby users ignore even critical warnings. Alert fatigue may in part explain why CDSSs appear to result in only modest improvements in adherence to recommended care. Although forcing functions can be used in CDSS to essentially prevent high-risk situations such as co-prescribing drugs with dangerous interactions, this approach can also have unintended consequences. Recent commentaries have called for CPOE and CDSS designers to tailor alerts to maximize safety while avoiding alert fatigue.

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. However, federal government incentives to hospitals to implement CPOE systems by 2012 have likely spurred a rapid implementation of CPOE and CDSS.

What's New in Computerized Provider Order Entry on AHRQ PSNet
Appropriateness of commercially available and partially customized medication dosing alerts among pediatric patients.
Stultz JS, Nahata MC. J Am Med Inform Assoc. 2014;21:e35-e42.
From physician intent to the pharmacy label: prevalence and description of discrepancies from a cross-sectional evaluation of electronic prescriptions.
Cochran GL, Klepser DG, Morien M, Lomelin D, Schainost R, Lander L. BMJ Qual Saf. 2014;23:223-230.
Evaluation of medium-term consequences of implementing commercial computerized physician order entry and clinical decision support prescribing systems in two 'early adopter' hospitals.
Cresswell KM, Bates DW, Williams R, et al. J Am Med Inform Assoc. 2014 Jan 15; [Epub ahead of print].
Computerized physician order entry: promise, perils, and experience.
Khanna R, Yen T. Neurohospitalist. 2014;4:26-33.
Are we heeding the warning signs? Examining providers' overrides of computerized drug–drug interaction alerts in primary care.
Slight SP, Seger DL, Nanji KC, et al. PLoS One. 2013;8:e85071.
Editor's Picks for Computerized Provider Order Entry
From AHRQ WebM&M
Bad Writing, Wrong Medication.
Beth Devine, PharmD, MBA, PhD. AHRQ WebM&M [serial online]. April 2010
Integrating Multiple Medication Decision Support Systems: How Will We Make It All Work?.
Josh Peterson, MD, MPH. AHRQ WebM&M [serial online]. May 2008
A Troubling Amine.
Elizabeth A. Flynn, PhD. AHRQ WebM&M [serial online]. September 2006
The Forgotten Med.
Russ Cucina, MD, MS. AHRQ WebM&M [serial online]. April 2005
Overriding Considerations.
Neil A. Holtzman, MD, MPH. AHRQ WebM&M [serial online]. December 2004
Incidence of adverse drug events and potential adverse drug events: implications for prevention. Classic icon
Bates DW, Cullen DJ, Laird N, et al; ADE Prevention Group. JAMA. 1995;274:29-34.
Unexpected increased mortality after implementation of a commercially sold computerized physician order entry system. Classic icon
Han YY, Carcillo JA, Venkataraman ST, et al. Pediatrics. 2005;116:1506-1512.
Types of unintended consequences related to computerized provider order entry. Classic icon
Campbell EM, Sittig DF, Ash JS, Guappone KP, Dykstra RH. J Am Med Inform Assoc. 2006;13:547-556.
Effect of computerized physician order entry and a team intervention on prevention of serious medication errors. Classic icon
Bates DW, Leape LL, Cullen DJ, et al. JAMA. 1998;280:1311-1316.
Role of computerized physician order entry systems in facilitating medication errors. Classic icon
Koppel R, Metlay JP, Cohen A, et al. JAMA. 2005;293:1197-1203.
Overcoming barriers to adopting and implementing computerized physician order entry systems in U.S. hospitals. Classic icon
Poon EG, Blumenthal D, Jaggi T, Honour MM, Bates DW, Kaushal R. Health Aff (Millwood). 2004;23:184-190.
Clinical information technologies and inpatient outcomes: a multiple hospital study.
Amarasingham R, Plantinga L, Diener-West M, Gaskin DJ, Powe NR. Arch Intern Med. 2009;169:108-114.
Unintended effects of a computerized physician order entry nearly hard-stop alert to prevent a drug interaction: a randomized controlled trial. Classic icon
Strom BL, Schinnar R, Aberra F, et al. Arch Intern Med. 2010;170:1578-1583.
Mixed results in the safety performance of computerized physician order entry. Classic icon
Metzger J, Welebob E, Bates DW, Lipsitz S, Classen DC. Health Aff (Millwood). 2010;29:655-663.
Electronic prescribing improves medication safety in community-based office practices.
Kaushal R, Kern LM, Barrón Y, Quaresimo J, Abramson EL. J Gen Intern Med. 2010;25:530-536.
Preventing Medication Errors: Quality Chasm Series. Classic icon
Committee on Identifying and Preventing Medication Errors, Aspden P, Wolcott J, Bootman JL, Cronenwett LR, eds. Washington, DC: The National Academies Press; 2007.
Focus on Computerized Provider Order Entry.
J Am Med Inform Assoc. 2007;14:25-75.
The Leapfrog Group.
c/o Academy Health, 1801 K Street, NW, Suite 701-L, Washington, DC 20006.
National Quality Forum.
601 Thirteenth Street, NW, Suite 500 North, Washington, DC 20005.
Cedars-Sinai doctors cling to pen and paper: transition to electronic medical records proves difficult.
Connolly C. Washington Post. March 21, 2005:A01.
Last Updated: October 2012