Category Archives: errors

Death from Branding

If you’re Apple, you want people to see the similarities between their iPod and their iPhone. However, if you are a drug manufacturer, you do not want similarities between adult and pediatric medicine.

Above are bottles of Heparin, manufactured by Baxter Healthcare. Both blood thinners, one of these vials is 1,000 times more concentrated than the other. Confusion between these two bottles killed infants at an Indiana hospital back in 2002. This article provides a good overview of past cases.

I actually remember reading about this back then, and thought “Wow, there’s a good human factors lesson. How awful that children had to die to bring it into the spotlight.”

Unfortunately, this lesson stayed unlearned, as two more children were administered the adult drug this week. Because these were the newborn twins of Dennis and Kimberly Quaid, who have already spoken out on 60 Minutes about medication mistakes, we may see the problem addressed more thoroughly in the drug industry.

On a final note, these cases touch on the human desire to blame other humans rather than the systems they interact with. In the Indiana case, a mother who lost her child was quoted as saying:

… who blames the nurses, not drug labeling, for her daughter’s death. “I don’t think it was from the label,” she said. “They are both blue, but one is lighter than the other. How could they mistake those?”

Change blindness, automaticity, expectation, fatigue, and time pressure are but a few of the factors that might have caused the error. Sometimes, it isn’t a case of someone not just “being careful.” This is actually a good thing: we can understand and solve human factors problems. We can’t make someone care.

Unusually quiet morning radio show

What if a Radio DJ hosted a morning show and no one heard?

Lesson learned! I will try to make certain to hit ‘publish’ at the end of this post.

From the article:

“”I’ve been doing the show three days a week for 10 months and always pressed the button at the right moment. Goodness knows why I forgot this time.

“Mr Dixon, the station’s only employee, will not fire his “excellent” breakfast show DJ, who is one of 35 volunteers who have learnt their radio skills from scratch.”

The Double-Bubble Ballot

U.S. news agencies are reporting on the California ballots that ‘may have lost Obama the California primary.’ The argument is that he would have pulled in the ‘declined to state’ voters (those who have not registered as either Democrat or Republican), but that because of a human factors error with the ballot, those votes may not have been counted. (The inference is that these voters would have supported Obama.)

Succinctly, declined-to-state voters have to ask for a Democratic ballot. Then they must fill in a bubble at the top of the ballot, saying that they wanted to vote in the Democratic primary. Obviously, many users might not do this, as it seems a redudant code… the ballot they are holding is the Democratic ballot, so why indicate again that it was the ballot they requested? If you look at the ballot below, it says at the top to “select party in the box below.” Of course, there is only one option, which makes it not much of a selection.

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It’s likely this area of the ballot was inserted to produce some interesting statistical information (rather than a pure answer of who received the most votes.) If only declined-to-state voters filled the bubble, you could get a count of how many of those voters came out to vote compared to other years, how many chose to vote Democrat, and which candidate received most of their support. While interesting (I would like to know all of those things) it complicates the purpose of primary voting: to count the number of Americans who support a particular candidate.

Why I am not a conspiracy theorist: People with the best of intentions make critical human factors design errors, even errors that cost people their lives (see “Set Phasers on Stun.”) Sometimes, these errors are created by specific good intentions, as in the Florida hanging-chad fiasco.

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The reason the choices were staggard on each side of the ballot was to increase the font size, supposedly making the ballot more clear for older voters. This perceptual aid was trumped by the resulting cognitive confusions. These ballot designs may suffer from a lack of user testing, but not from an intentional ploy to keep declined-to-state voters from being counted or to get Pat Buchanan more votes.

Thus, let’s tackle the problem rather than using ‘double bubble’ for a slow news day. Why don’t we demand all ballots and voting machines be user tested? (Security is another issue, for another blog.) If you have an idea of what action to take, please comment so a future post may provide detailed instructions.

NPR covers a good bit of the HF field in one conversation with two doctors

All Things Considered interviewed Dr. Peter Pronovost this weekend about the checklist he developed for doctors and nurses in busy hospitals. On a topical level, this illuminated the working memory demands of hospital work and statistics on how easy it is to err.

As an example, a task analysis revealed almost two hundred steps medical professionals do per day to keep the typical patient alive and well. On average, there was a 1% error rate, which equates to about two errors per day, per patient.

Pronovost introduced checklists for each type of interaction, which resulted in Michigan hospitals going from 30% chance of infection (typical across the US) to almost 0% for a particular procedure.

Could something as simple as a checklist be the answer? No, because this intervention wasn’t “just” a checklist.

Whether trained in these areas or not, the doctors interviewed had to understand:

Team training: Nurses are trained not to question doctors, even if they are making a mistake. Solution: Pronovost brought both groups together and told them to expect the nurses to correct the doctors. (Author note: I’d be interested to see how long that works.)

Social interaction: In an ambigous situation, people are less likely to interfere (e.g., the doctor didn’t wash his or her hands, but the nurse saw them washed for the previous patient and thinks “It’s probably still ok.” Checklist solution: eliminate ambiguity through the list.

Effects of expertise: As people become familiar with a task, they may skip steps, especially steps that haven’t shown their usefulness. (e.g., if skipping a certain step never seems to have resulted in an infection, it seems harmless to skip it). Checklist solution: enforce steps for all levels of experience.

Decision making: People tend to use heuristics when in a time-sensitive or fatigued state. Checklist solution: remove the “cookbook” memory demands of medicine, leaving resources free for the creative and important decisions.

Intuition vs Experience with Roundabouts

Some people might say a traffic circle is obvious. There is only one way to go.. who yields might be more difficult, but at least we are all driving in the same direction.

Not so.

The following two articles come down on the side of experience for the usability of roundabouts.

New Traffic Circle Causes Confusion

Death-crash car launches off the road and into a first floor flat

I am sure the designers believed that if millions of people in London and hundreds of thousands in New Orleans can handle a roundabout, these citizens of a town so small they don’t even bother to mention where it is would do fine.

Why Human Factors is more than providing safety equipment

The new math and physics building is going up outside my window at North Carolina State. I see the workers out there each day, and as the building gets higher they are obviously required to don different safety gear.

The fuzzy picture below shows two workers on the top level (7th floor) and the green highlight is my outline of the full body harness and safety cord the man is wearing. Indeed, it seemed necessary as whatever tool he is using seems to push him off balance with every use (some sort of nail gun?)

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However. Unlike the man behind him, this worker has not attached his safety cord to anything. It merely drags along behind him as he walks around the platform and crawls in and out of the scaffold. In fact, it seems to get in his way when the clasp on the cord catches on the corrugated surface of the platform.

More medical errors–Operating on the wrong side of the patient’s brain!

There sure seem to be lots of medical errors in the news lately. No mention of human factors:

The most recent case happened Friday when, according to the health department, the chief resident started brain surgery on the wrong side of an 82-year-old patient’s head. The patient was OK, the health department and hospital said.

In February, a different doctor performed neurosurgery on the wrong side of another patient’s head, said Andrea Bagnall-Degos, a health department spokeswoman. That patient was also OK, she said.

But in August, a patient died a few weeks after a third doctor performed brain surgery on the wrong side of his head. That surgery prompted the state to order the hospital to take a series of steps to ensure such a mistake would not happen again, including an independent review of its neurosurgery practices and better verification from doctors of surgery plans.

We can surmise from the short news article that the source of the problem seems to be working memory??

In addition to the fine, the state ordered the hospital to develop a neurosurgery checklist that includes information about the location of the surgery and a patient’s medical history, and to put in place a plan to train staff on the new checklist.

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Patient record mistakes

LOS ANGELES – The recent chatter on a popular social networking site dealt with a problem often overlooked in medicine: mistakes in patients’ medical charts.The twist was the patients were doctors irked to discover gaffes in their own records and sloppy note-taking among their fellow physicians.

Errors can creep into medical charts in various ways. Doctors are often under time pressure and may find themselves taking shortcuts or not fully listening to a patient’s problems. Others rely on their memory to update their patients’ files at the end of the day. Other mistakes can arise from illegible handwriting or coding problems.

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“From the Doctor’s Brain to the Patient’s Vein”

It appears that HFB needs an entire section devoted to medical error. This is not surprising in light of the thousands of Americans who die from preventable errors each year.

The latest comes from Tanzenia where confusion about patient names earned brain surgery for a twisted knee, and knee surgery for a migraine sufferer.

Mr Didas who had been admitted for a knee operation after a motorbike accident is still recovering from the ordeal – he ended up unconscious in intensive care after his head was wrongly operated on. And chronic migraine sufferer Emmanuel Mgaya is likewise, still recovering from his unplanned knee surgery. The blunder was blamed on both patients having the same first name.
But a hospital official, Juma Mkwawa said it was the worst scandal that had happened at Muhimbili hospital and that, “sharing a first name cannot be an excuse”. The two surgeons responsible have been suspended. (BBC)

Before anyone retreats into the comfort of “that wouldn’t happen here,” I suggest a look at the growing literature on similar medication names and their consequences.

It is easy to be the bearer of sad stories and ill tidings. I would rather on a note for a hopeful future. Below are researchers and companies dedicated to identifying and eliminating causes of medical error.

Please add more in the comments section if you know someone working in this important context.

“Set Phasers on Stun” still relevant in healthcare industry

Center Treats Wrong Side Of Patient’s Brain

DETROIT — A patient undergoing treatment at the Karmanos Cancer Institute in Detroit received a dose of radiation on the wrong side of the brain, according to a report filed with the United States Nuclear Regulatory Commission.

According to the report, a crucial piece of information was misread prior to treatment with a gamma knife, which delivers a targeted form of radiation therapy that zeros in on specific locations in the brain.

The patient went through a routine MRI (magnetic resonance imaging) scan of the brain just before the procedure, but went into the scanner “feet first,” rather than the standard practice of head first, the document said.

“The gamma knife-authorized medical physicist failed to recognize the scanning error when importing the MRI images into the Gamma Knife treatment planning computer, and subsequently registered them as head first,” the report said. “This resulted in the wrong side of the patient being targeted and treated.”

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What went wrong? Deviation from standards (if there are standards)? Too-busy doctors? I’ll be interested to see who gets the blame.