Adverse drug events (ADEs) are a significant cause of mortality, hospitalization, and emergency department visits. 1–4
One important contributing factor to ADEs is drug–drug interactions (DDIs). In one study conducted at two tertiary care hospitals, DDIs accounted for 3% of ADEs observed in adult patients. 5
The presence of specific DDIs has been associated with a 20-fold increase in the risk of hospitalization among elderly individuals. 6
The overall prevalence of potentially serious DDI combinations in adult outpatients has been estimated at less than 1%. 7
However, for specific DDIs, the prevalence may be much higher. For example, the warfarin—NSAID interaction has been reported to be as high as 24% of patients receiving warfarin. 8
Numerous studies have demonstrated that the use of computerized physician order entry (CPOE) can be an efficient means for decreasing omission errors, 9
transcription errors, 10
serious medication errors, 11
and injury from adverse drug events. 12
The use of CPOE can also substantially reduce medication errors when clinical decision support features such as drug-disease contraindications and DDI alerts are incorporated into the system. 13–17
However, implementation of CPOE can have drawbacks as well. Ash and colleagues provided many examples of how implementing patient care information systems, which included CPOE, could foster rather than reduce errors. 18
In addition, further negative emotions such as shame, guilt, anger, and annoyance, can arise in clinicians as a result of various CPOE features and implementation strategies. 19
Users of CPOE systems have reported both positive and negative views of these systems. A survey of health providers at two military health care facilities found that CPOE was generally well liked, with an overall satisfaction of 3.8 on a five-point scale where “5” represented the highest satisfaction level. 20
Another survey conducted by Lee et al. at Brigham and Women’s Hospital in Boston found that respondents had reported a reasonable level of overall satisfaction with their CPOE system (mean = 5.1 on a seven-point scale). 21
A prospective study conducted by Rind et al. indicated that 44% of physicians considered computerized reminders helpful while 28% felt the reminders were annoying. 22
In an evaluation of the impact of an inpatient CPOE system on patient care, most nurses had more positive views than physicians. 23
More recently, Murff and Kannry assessed physician satisfaction with two CPOE systems and reported that respondents were more satisfied with the Department of Veterans Affairs (VA) computerized patient record system (CPRS) (mean = 7.2 on a nine-point scale) than with a commercially available product (mean = 3.7). 24
Several challenges in the introduction of an electronic medical record (EMR) system were identified by Scott et al. 25
Many EMR users felt excluded from the selection process for the EMR program, leading to doubts and resistance to use the program. There were also concerns about reduced clinician productivity.
Although CPOE has been evaluated in numerous studies, relatively few published studies have been conducted to specifically examine computerized DDI alerts. 26–28
Glassman et al. surveyed VA clinicians and found 55% of respondents believed that drug interaction alerts improved their ability to prescribe safely; whereas only 9% disagreed. 27
Nevertheless, 55% of clinicians perceived that poor signal-to-noise ratio moderately or greatly limited use of the alerts. In a survey of general practitioners in the UK, 90.4% of respondents agreed that drug interaction alerts were a useful tool in prescribing but 73.5% agreed that the alerts were sometimes not applicable or relevant to the patient. 28
With the implementation of CPRS throughout the VA health care system in the late 1990s, prescribers now enter prescription orders electronically for review and verification by a pharmacist before dispensing. As a part of the order entry system when two products are prescribed that may interact, the prescriber is alerted to the potential problem. The Department of Veterans Affairs National Drug File Support Group is responsible for the drug interaction package. This working group is responsible for identifying and maintaining the clinical decision rules to trigger DDI alerts. The VA classifies interactions into two groups: “significant” or “critical.” Combinations are considered candidates for DDI alerting if the interaction is pharmacokinetic in nature, such as alterations in absorption, plasma protein binding, enzyme induction or inhibition, or interference with renal excretion. An example of a significant interaction is coprescribing of ciprofloxacin and phenytoin. An example of a critical interaction is the combination of fluvoxamine and phenelzine. All critical alerts require a reason to override the alert and allow the order to be placed. A common complaint among VA practitioners is that many DDI alerts are erroneous because the alerts are based on VA drug classes, not necessarily specific drug products. For example, ophthalmic erythromycin is not viewed differently from oral erythromycin in terms of the potential for a drug interaction. Therefore, prescribers may get multiple nuisance DDI alerts on the same order which can be very aggravating to busy clinicians.
DDI alerts are presented first when an order dialog is accepted and again when the order is actually signed. It is at signature that a reason for overriding a critical DDI would be required, but there is no way to enter a reason for overriding a less than critical DDI. In addition to the alert being provided to the prescriber, the pharmacist will also be subsequently alerted during the verification process if the prescriber decides to continue with the prescription order despite the DDI alert. Unlike many settings where CPOE has just been recently introduced, VA health practitioners have had sufficient experience with CPOE to identify general likes and dislikes. The purpose of this study was to assess VA prescribers’ and pharmacists’ adaptation to the CPRS and their views on a series of statements about computer-generated inpatient and outpatient DDI alerts. To make suggestions for improving the alerts, we also assessed and compared prescribers’ and pharmacists’ preferences of possible changes to DDI alerts.