Confirmation bias threatens patient safety, but can be overcome

Sometimes people see or hear what they expect, not real information

Is confirmation bias lurking in your hospital, waiting to cause havoc for even the most skilled, well-intentioned clinicians? This mental fault allows one to see or hear what is expected or desired, rather than what actually is. It has led to adverse events in many industries, and healthcare is exceptionally vulnerable.

Tufts Medical Center in Boston is dealing with the tragic results of confirmation bias, but the institution has implemented safeguards to keep the risk at bay, says Lynn Worley, RN, JD, CPHRM, senior risk manager and assistant general counsel at Tufts Medical Center. The family of a Tufts patient is suing the hospital after a surgeon injected the wrong dye into her spine, when the surgeon mistakenly assumed it was the correct dye he had asked for. The patient died the next day from the effects of the dye. The surgeon was baffled as to how he, the nurse who handed it to him, and others along the line failed to notice that the label clearly stated it was a different dye and included a warning not to use it in the spine. (For more on the adverse event, see the article on p. 111.)

The case is a good example of confirmation bias, says Tufts Chief Medical Officer Saul Weingart, MD, MPP, PhD. The surgeon and other clinicians "saw what they expected to see" even though the label clearly said otherwise, Weingart explains. Confirmation bias can take many forms, he says, from unconsciously giving more weight to data that support your political views to actually reading different numbers on a lab value or different words on a label.

The dye error and an unrelated incident involving an embolism prompted Medicare to conduct a full-scale inquiry into Tuft’s practices in February 2014. Medicare’s findings and the Tufts’ own investigation led to a series of hospital-wide improvements. As a result of the dye error and the subsequent root cause analysis, Tufts now require surgeons and operating room nurses to submit detailed written medication orders to pharmacists, in addition to other new checks in the system.

"All adverse events teach us something," Worley says. "We stopped and took a pretty hard look at all our systems. Among the things we looked at, one of the first was the process of orders from a physician to a circulating nurse to the pharmacy."

Written orders required

Worley investigated how other hospitals performed those tasks in the OR and found that some used "written verbal" orders — orders dictated to and written by a nurse when the doctor cannot write it, such as when a surgeon is scrubbed — and some just used verbal orders. Seeking the best practice to promote safety, Worley and her colleagues decided that a policy requiring written orders every time, for every step in the process, was the way to go. Tufts had always required written orders for all care outside the OR, but now surgery is included.

Written verbal is allowed as long as a specific process is followed.

"A nurse takes an order, writes the order down, and reads it back to the physician to make sure everyone is on the same page," Worley says. "We thought this was the right policy even for the OR, where things sometimes happen quickly and verbal orders are common. The fact that the OR is a highly critical situation and fast-moving made a compelling argument that the orders should be written."

The policy doesn’t end there. For any medication, the written order must include the name of the drug, the route of administration, the patient’s name, and any allergies.

"This was a team effort," Worley says. "Pharmacy staff were instructed that no written order means no medication, period. If a written order came without necessary information like allergies, the pharmacy refused to fill those. They understand that this is what we need to do to keep our patients safe, so if pharmacy staff do not receive a completely filled-out order, they simply do not give up the medication."

To keep the policy practical for the OR, Tufts worked with specialty leaders to develop order sets for each service to cover the most commonly used medications. Physicians can sign off on the order set or vary it as needed, before surgery begins.

Formulary changed

Prompted by the adverse event with the dye in a spinal procedure, Tufts assessed all use of contrast media in surgery. Worley found that the dyes are very infrequently used. The dye media are available in ionic and non-ionic types, and ionic contrasts in particular are used only for genito-urinary surgery at Tufts.

With that limited use in mind, Tufts went to the pharmacy leaders and had the ionic contrast medium removed from the formulary so that it cannot be ordered, intentionally or accidentally, unless it is for genito-urinary surgery. The order must be accompanied by an attestation that it is to be used for that particular type of surgery.

Working with the radiology department, Worley and her colleagues also revised the formulary so that there is only one type of non-ionic contrast available, in three strengths. Those three options for non-ionic contrast medium satisfy the needs of all other types of surgery, Worley explains. Interventional radiology also specified the acceptable use of the three strengths of non-ionic contrast for specific procedures.

"The nurses are on high alert for these medication orders, particularly with contrast media," Worley says. "All orders for contrast go through the pharmacy, and the pharmacy knows the route before it is ever dispensed."

The improved medication ordering system is intended, in part, to reduce the chance of confirmation bias letting the wrong drug make its way to the bedside or the OR, Worley says. Confirmation bias can happen at many stages in the ordering system, so the written orders and specific requirements help minimize that risk. If those checks work properly, there is little likelihood that the surgeon will be susceptible to confirmation bias at the last step in the process.

Education strategies

Tufts used multiple modalities to first alert the staff and physicians about the risk of confusing contrast media and then to educate them about the new policies and procedures, Weingart says.

All clinical staff received an email immediately after the adverse event alerting them to the possible confusion, and then they attended multiple staff meetings to learn the new procedures. Nurses were required to complete learning modules by computer, and education also was required for surgeons and anesthesiologists. A weekly memo from Tufts leadership also reiterated the new policies and procedures, as did Tufts newsletters and other publications.

"Real time education also occurred when a person would have a medication order that did not meet the requirements," Weingart says. "The receiving person would explain the new process and require a proper order before providing medication."

Pharmacy also conducted its own education program to clarify what pharmacy staff members should require before fulfilling an order. Tufts also audits the medication ordering system periodically, and the most recent check found 100% compliance.

Worley says that after learning from their adverse event, she recommends highly that all ORs require written verbal orders. "It’s a hard lesson to learn," she says. "If you’ve never had a problem before, don’t wait for it. Get a handle on this before it becomes a problem."