Pharmacists who misfill prescriptions often share lack of working memory

Intervention can redirect actions and reduce errors

The system often is blamed when pharmacists fill prescriptions incorrectly. For example, pharmacists may say they were distracted by a busy workplace, resulting in the "misfilling" of the orders.

A new report, however, says some pharmacists are predisposed to medical errors due to individual factors, such as a lack of working memory. Without working memory, pharmacists are more apt to struggle with multitasking. The good news is that with proper intervention and a goal-setting program, pharmacists can recognize the situation and learn to minimize the likelihood of future medical errors.

This report was presented to the Florida Board of Pharmacy on April 14 by Carsten Evans, MS, PhD, assistant dean at Nova Southeastern Univer-sity (NSU) College of Pharmacy in Fort Lauderdale, FL. The report was the result of a three-year study that analyzed pharmacists who were directed to the NSU program as a result of their misfills. These pharmacists were required to satisfy an educational component that was assigned to them as part of a judgment from the board for making a medication error.

The report introduced two issues that were critical in the development of the NSU medical error remedial program, Evans says. The first issue was a review of the fact that the leading reported cause of medical errors (according to U.S. Pharmacopeia in Rockville, MD) has always been performance deficit. Performance deficit is defined as a cause of error that may not be attributed to any specific cause, a reason for error that cannot be explained, or the person was educated and/or trained and should have known better.

The second issue described the primary factor contributing to error, distraction, as an event that interferes with or interrupts an individual from concentrating on his or her original focus of attention. After defining these two issues, the researchers focused on developing a program based on human behavior, Evans says.

The philosophy of the program design was to determine which measures of individual characteristics predict pharmacists who commit medical errors. "The measures selected were cognitive attributes such as planning, organizing, the ability to multitask — comprised of working memory, attentional control, and learning speed skills — and personality characteristics of conscientiousness and emotional stability," he says.

The NSU Med-Error Remedial program was first presented to the Florida Board of Pharmacy in May of 2001. It was designed by Evans; Robert Pihl, PhD, professor of psychology and psychiatry at McGill University in Montreal; Jordan Peterson, PhD, professor of psychology at the University of Toronto; and Daniel Higgins, PhD, professor at Harvard University in Boston.

This study compared the pharmacists mandated by a state board of pharmacy for misfill errors to a control group of pharmacists on computerized neuropsychological tasks and personality tests, offered by ExamCorp ( The three-year results found no differences in personality, but did find highly significant decrements among members of the medical error group for working memory, attentional control, and verbal organization when compared with the controls.

"We went into this looking for similarities," Evans says. The similarities were simple: The people who make most of the errors have no working memory. "The pharmacists who were randomly selected out of an audience for the control group, for the most part, had working memory."

Working memory is the ability to sustain multiple thoughts at the same time. On the ExamCorp test, it has a scale measure range of 0-99, he notes. "No" or "very little" working memory is considered less than 10 on the scale. It was very common to find the misfill pharmacists score less than 10 over the three-year period. "We have people who have zero working memory who are filling prescriptions," Evans adds.

These pharmacists can be productive when they single-task. Their stress level, and possibility of error rate, increases when they try to handle more than one task at a time. Evans also found that while some people are born with a lack of working memory, some lose it after undergoing major transitions in life.

The results were not gender-based. Age, however, is a factor. "As we age, our brain cells are not replaced as fast and our working memory capacity decreases," he says.

Logistic regression of test scores was highly significant in successfully determining group membership, Evans says. The findings were unrelated to workload. "The results point to the importance of considering individual factors in making errors in the practice of pharmacy. These measures allow us to predict the probability of pharmacists to error and to determine those in need of intervention. Selection and intervention are the two areas where specific steps can be taken to dramatically reduce the risk of pharmacist errors."

Intervention is the last component of the NSU Med-Error Remedial program. Research data show that the program’s process can improve working memory and that it is possible to improve organizational and planning skills, Evans says. Interventions are directed approaches toward individual factors in minimizing medical errors. The interventions include testing, discussion of individual results (with the program psychologist), required readings, and a unique goal-setting requirement for the participants.

Included in the intervention/training are techniques that can modify risk factors such as individual characteristic job matching, stress-reduction interventions, goal-setting programs, and exercising — both mental and physical. The key is finding ways to relieve stress, Evans says.

"Once [the pharmacists] find ways to relieve the stress, they can get along in a multitasking situation because they take every task as an individual one. They learn how not to be harassed into doing more than one thing at a time."

The last stage of the goal-setting program helps the pharmacists take charge, gets them organized, and gives them direction, Evans says. "It decreases their stress and anxiety."

The pharmacists usually are happy to find out why they may have been struggling in their jobs. They repeatedly make the errors because they don’t like what they are doing, he says, but they don’t understand why they don’t like it. "They are multitasking when they should be single-tasking. [For instance], they don’t like answering the phone when they are trying to talk to people."

These interventions have demonstrated that they can remediate predictive risk factors of pharmacists and improve their level of functioning for these traits, Evans says. The program gives the pharmacists the tools to avoid the situations that got them into trouble. "It actually improves their health," Evans says. "It makes their life in the present more meaningful. If they can put their lives in order, chances are that they can understand their limitations."

These pharmacists appreciate the fact that they become empowered with the knowledge of why they should not work in areas of the pharmacy operation that require stressful multitasking abilities, he adds.

In conclusion, the three-year results of the report have demonstrated that individual differences are an important factor in medical errors, Evans says. "These differences are measurable. Working memory is a critical attribute, and these factors of concern, like working memory, can be remediated."