The worldwide incidence of medication administration errors varies between 6.6% and 44.6% for all doses administered by nurses (Tissot et al. 1999; Barker et al. 2002; van den Bemt et al. 2002; Greengold et al. 2003; Lisby et al. 2005). The proportion of these errors with the potential to harm patients, such as permanent disability and death, is estimated at 7% (Flynn et al. 2002). The importance of addressing this problem is recognized internationally (Kohn et al. 2000; Nicklin et al. 2004; World Health Organization 2004).
Medication errors are found at every stage of the medication use process with one-third of medication errors harming patients being associated to the medication administration stage (Leape et al. 1995). From a medication safety perspective, the medication administration stage is different from other stages for two reasons. Nurses act as safeguards against errors intercepting up to 86% of all errors made by physicians, pharmacists, and others involved in providing medications for patients (Leape et al. 1995). Second, medication administration has very few safeguards against errors because it happens at the end of the medication use process (Aspden 2007). For these reasons, improvements to the medication administration process could tremendously maximize medication use safety within health care organizations.
Medication errors have been defined as “the failure to complete a planned action as it was intended, or when an incorrect plan is used, at any point in the process of providing medications to patients” (Canadian Patient Safety Institute 2003, p. 31). Medication administration errors have been divided into a number of categories such as wrong time, unauthorized drug, extra dose, wrong dose, omission, wrong route, and wrong form (Flynn et al. 2002). Wrong time medication administration errors are the most frequent comprising 42.8% of all medication administration errors followed by omission with 30.2% (Barker et al. 2002). However, wrong time errors are often considered clinically unimportant, although this perspective has been debated (Kopp et al. 2006). This incertitude about the clinical significance of wrong time errors explains why, at times, researchers studying contributing factors to medication administration errors are performing their analysis with and without the wrong time administration error category.
Studies on contributing factors help us to understand the underlying causes of medication administration errors. Such contribution is urgently needed to assist in the development of effective prevention strategies (Vincent 2006). In line with this goal, James Reason's work (Reason 1990) has played a pivotal role in shifting from a person-centered to a system perspective on potential contributing factors to medication errors (Page 2004). A system approach posits that, although individuals are responsible for the quality of their work, more medication administration errors can be avoided by focusing on the system rather than solely on individuals. Consequently, if the system approach is correct, one of the first steps in a medication administration error reduction program is to systematically document system-related contributors to such errors.
When nurses are surveyed, work interruptions appear among the most prominent of the system-related factors (Cohen et al. 2003; Balas et al. 2004; Stratton et al. 2004; Armutlu et al. 2008). Work interruptions entail a halt of the activity being performed for monitoring purposes or to carry out a secondary task (Hopp et al. 2005). Distractions, on the other hand, are detected by a different sensory channel from those of the primary task, and may be ignored or processed concurrently with the primary task; this is not the case for work interruptions (Speier et al. 2003). However, both concepts are related. Distractions are the necessary precursor of work interruptions (McFarlane & Latorella 2002).
A number of hypotheses have been formulated to explain how work interruptions might result in human errors. The mechanisms underlying this contribution could depend on the task performance level (Reason 1990). Three levels of task performance have been proposed: skill-based, rule-based, and knowledge-based performance (Rasmussen 1986). Skill-based performance is mostly automatic and is found in routine actions. These routine actions require dispersed attentional checks to ensure proper task completion. Work interruptions during skill-based performance may interfere with these required attentional checks and lead to slips and lapses (Reason 1990). At the other end of the spectrum, with knowledge-based task performance, nurses must rely on conscious analytical processes and stored knowledge to solve problems. At this level of performance, work interruptions add to the amount of information being processed, and if the demands for cognitive resources are higher than those available, task performance is negatively affected (Wickens & Hollands 2000).
Interventions addressing the frequency of work interruptions in the interests of maximizing medication administration safety certainly represent a promising avenue, considering work interruptions could lead to human errors (Potter et al. 2005). However, before intervening, any evidence on the frequency, characteristics, and potential contribution of interruptions to medication administration errors, evidence that goes beyond the data obtained in the surveys, should be described and assessed systematically. A thorough review of the evidence is essential to ensure that future actions by clinicians, administrators, policy makers, and researchers are informed by the best available information.