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March 13, 2018

How lessons learned from plane crashes can improve patient safety

Written By: Silke Schmidt

Medical error is the third-leading cause of death in the United States: Each day, almost 1,000 patients die, while another 1,800 additional patients are harmed in some way.

 Douglas Wiegmann
Douglas Wiegmann

These numbers are stunning, though also controversial, says Douglas Wiegmann. “We don’t yet have a way to systematically track these events, and it’s not always straightforward to pinpoint the primary cause of a patient’s death,” he explains. “But there’s no doubt that we have a major problem.”

To tackle that problem, Wiegmann, an associate professor of industrial and systems engineering at the University of Wisconsin-Madison, is now leading a pilot study for analyzing and correcting the root causes of patient harm events in the UW Health system.

The study, rolled out in January 2018, builds upon his extensive experience with root cause analysis (RCA) in other industries and is funded with $150,000 from the UW Institute for Clinical and Translational Research. Wiegmann and his UW Health colleagues will develop a toolkit—consisting of guidelines, interview questions, checklists and causal factor diagrams—that helps stakeholders decide which corrective steps they should take to reduce the frequency of patient harm events.

For illustrating the types of medical error that may occur in a hospital, Wiegmann shares a hypothetical example: A respiratory therapist changes the oxygen mask on an asthma patient. While she is re-attaching the mask to the oxygen tank, she is paged for an emergency in another room. Believing that the mask is properly attached, she leaves, only to be paged again five minutes later: Since oxygen no longer flowed through the mask, the patient suffered a cardiac arrest and died.

Today, Wiegmann says, a root cause analysis of that event might go something like this: Hospital staff review the existing protocol, which includes never leaving a patient on an oxygen mask until all vitals have been checked; they remind the therapist, her colleagues and supervisors to follow this protocol at all times; and they have connectors added to all oxygen hoses that will click when properly attached to the tanks.

“That’s like putting a Band Aid on a single cut,” Wiegmann says. “It probably reduces the probability of repeating this particular event, but it doesn’t make the entire system better and safer.”

To achieve that goal, tougher and deeper questions are needed: Has this type of event almost happened before, and if so, what was done about it? What guidelines did the therapist receive from her supervisor for responding to an emergency call? What are the organizational policies that give the supervisor the ability to provide guidance? Was the therapist’s schedule already overloaded when she was paged? How can she quickly page another nurse when she is unable to respond immediately?

But in order to consistently ask these big-picture questions for every patient harm event, the hospital staff who conduct the root cause analysis need to be trained to become investigators—just as Wiegmann was trained to be an investigator for the National Transportation Safety Board when his research interests were focused on equipment failures and human error in the aviation industry.

Charged with analyzing the root causes of plane crashes and space shuttle disasters, he and his colleague Scott Shappell (now at Embry-Riddle Aeronautical University) studied hundreds of accident reports containing thousands of causal factors to improve the aviation industry’s safety protocols. With their background in human factors engineering, which applies an understanding of human capabilities and limitations to systems design, they developed the Human Factors Analysis and Classification System (HFACS), a toolkit that can be modified for use in other industries.

“Our work in the aviation industry has helped change its organizational structure and culture to give safety professionals more decision-making authority, and I do think this has helped prevent future accidents,” Wiegmann says. “For the first time in the history of modern aviation, we had no fatal airplane crashes in the United States in 2017.”

Since plane crashes tend to be catastrophic and highly visible, the aviation industry has invested in better safety protocols for almost 70 years. That’s a stark contrast with the healthcare industry, according to Wiegmann. Although it has recognized its growing need for root cause analyses, the success of the tools it has used during the past decade or so has been limited.

That means the time is now ripe to develop the next generation of tools: improved infrastructure and staff training, using the methods that have already proven their worth in the aviation industry. With data from the completed pilot study, Wiegmann and his colleagues plan to submit a larger proposal to federal funding agencies in order to measure how effective the new tools are in reducing patient harm events. “

At 18 months, our pilot study is too short for this kind of comprehensive evaluation, but in order to start a larger study, we first need to know what works and what doesn’t,” Wiegmann says. “Given my experience with other industries, I believe a continued investment in root cause analysis is our best bet for improving patient safety in hospitals around the country.”

Wiegmann’s academic collaborators at the UW School of Medicine and Public Health include Jeff Pothof (Department of Emergency Medicine) and Tosha Wetterneck (Department of Medicine, Division of Internal Medicine). His stakeholder collaborator is Amy Topel, who directs patient quality and safety at UW Health.