Pat McNees, writer, editor,
personal historian

Expert explores the anatomy of medical error

by Pat McNees

This piece was written for NIH Clinical Center News, September 2006

“Humans err,” said Dr. Saul N. Weingart, vice president for patient safety and director of the Center for Patient Safety at Dana-Farber Cancer Institute. “Training, communicating, and reminding are weak interventions,” said Weingart in a sweeping analysis of medical error, in a Grand Rounds lecture for NIH fellows in the Clinical Center last month. “Only by probing deeply can we understand the conditions that lined up to allow something unfortunate to happen. You’ve got to change the system.”

“Don’t rely on memory or vigilance,” said Weingart, “or expect people to perform well when fatigued.” Simplify routines, reduce handoffs, build in redundancies and provide better information. Create forcing functions (making it impossible to do action B without precondition A). Make use of best practices—bar coding, for example, and repeating verbal orders (“the Starbucks rule: I’d like a low-fat no-foam latte”).

Recognize missteps for what they are. Cognitive psychologists recognize three models of error in human performance; skill-based, rule-based, and knowledge-based. Human factor scientists call skill-based errors slips and rule-based and knowledge-based errors mistakes.

Skill-based behavior is rapid, effortless, unconscious—things you do automatically, such as brushing your teeth, buttoning your shirt, driving to work. Characteristic slips involve
· Capture (you’re supposed to do one sequence of steps, A,B,C,F, and instead you do ABCD, because ABCD is more common—as when you load up the family car for vacation and absentmindedly drive toward the office)
· Description error (correct action, wrong object—pouring syrup in your coffee or milk on your pancakes)
· Associative activation (having the wrong cue trigger a particular behavior—the doorbell rings and you answer the phone)
· Loss of activation (striding purposefully into a room and not remembering why you are there).


“These slips are common across all cultures,” says Weingart. “They are part of the human phenotype.” We’re built to perform many functions on an unconscious level so that we can think about other things that are more interesting and important. “But those automatisms allow us to get into trouble. And they are degraded by the things you’d expect, such as fatigue, illness, alcohol, sleep deprivation, and boredom.”

Rule-based behavior (when it’s raining, take an umbrella) is important in medical training. Using mnenomics, we train physicians in rule-based behaviors with code algorithms, said Weingart. “The trick is to apply it in the correct setting.” Rule-based mistakes occur when we apply the wrong rule — for example, going down a code algorithm but choosing the wrong arm.

Knowledge-based behavior involves solving novel problems, coming at them afresh. Knowledge-based mistakes, of which there are many, have to do with biased memory and intellectual convenience. We like to use the solution we used last time, or we don’t like to change our mind once we’ve come up with an initial hypothesis, or we’re overconfident about what we decide.

Knowing we are faulty machines and that errors are inevitable, said Weingart, we must design medical care systems that make those errors transparent and reduce the number of preventable adverse events and close calls—paying special attention to high-risk patients, “those with the least physiological reserve.”

It’s important, says Weingart, to take care of yourself, take care of the system, and reduce blame and shame. “If we’re not free to talk about errors,” he said, “we’ll never learn from them.”

Saul N. Weingart, MD, PhD, a national expert on reducing the prevalence and burden of medical error, is vice president for patient safety and director of the Center for Patient Safety at the Dana-Farber Cancer Institute and an associate professor at Harvard Medical School. He lectured in Lipsett Auditorium on August 2, 2006.

For a fuller discussion of the three models, see Lucius Leape, “Error in Medicine” JAMA, Dec. 21, 1994, 1851-57.

In 1999 the Institute of Medicine published its report, To Err Is Human:Building a Safer Health System, which presented a strategy by which government, health care providers, industry, and consumers could reduce preventable medical errors. This report led to several others, which an educated consumer could use as a checklist on how not to be the victim of hospital-caused medical problems (above all, make sure whoever does a procedure on you washes their hands first).

In February 2000, the Quality Interagency Coordination Task Force (QuIC) issued a report, Doing What Counts for Patient Safety: Federal Action to Reduce Medical Errors and Their Impact, listing more than 100 activities needed to:
1. Create a national focus on reducing errors.
2. Develop a knowledge base for learning about errors' causes and effective error prevention.
3. Ensure accountability for safe health care delivery.
4. Guarantee that patient safety practices are implemented.

The Institute for Healthcare Improvement (IHI) announced the 100k lives Campaign, through which healthcare organizations, by implementing one or more of six specific evidence-based practices, could join a campaign to potentially prevent 100,000 avoidable deaths. Six interventional measures were identified as crucial to improving patient safety:
* Deploying rapid response teams at the first sign of patient decline.
* Delivering reliable, evidence-based care for acute myocardial infarction (AMI) to prevent deaths from heart attack (for example, give patient an aspirin).
* Preventing adverse drug events (ADE) by implementing medication reconciliation.
* Preventing central line infections by implementing a series of scientifically grounded interdependent interventions.
* Preventing surgical site infections by reliably delivering appropriate antibiotics and other specific steps.
* Preventing ventilator-associated pneumonia by implementing a series of scientifically grounded interdependent interventions.

To this it added new interventions targeted at harm
* Prevent harm from high-alert medications... starting with a focus on anticoagulants, sedatives, narcotics, and insulin
* Reduce surgical complications... by reliably implementing all of the changes in care recommended by SCIP, the Surgical Care Improvement Project (www.medqic.org/scip)
* Prevent pressure lcers... by reliably using science-based guidelines for their prevention
* Reduce methicillin-resistant Staphylococcus ureus (MRSA) infection…by reliably implementing scientifically proven infection control practices
* Deliver reliable, evidence-based care for congestive heart failure... to avoid readmissions
* Get Boards on board … by defining and spreading the best-known leveraged processes for hospital Boards of Directors, so that they can become far more effective in accelerating organizational progress toward safe care

Following are links to websites and reports that deal with improving patient safety and hospital staff performance. A quick look at these lists will give you a checklist of things to watch for when you or a loved one checks into a hospital. For one thing, you'll make sure healthcare providers wash their hands between patients and activities!