Some of the comment in this thread carries the implication of "I don't know what is wrong with pilots now: these things did not happen in my young days."
Well, they did.
James Reason, who was the original developer of the "swiss cheese model", arrived at it many years ago when he realised that all humans were inescapably subject to lapses of concentration, errors of judgement and dissociation: that is, where the brain decides to do one thing but the hands do another.
Here he is talking to Norman Swan in
an Australian Radio National transcript in 2005:
Norman Swan: Hello and welcome to The Health Report with me Norman Swan. Today an interview in our summer series with enormous implications beyond health to almost any walk of life and industry. 2005 unfortunately was a big year for light plane crashes in Australia, at least some of which were alleged to be the result of pilot error. It was also a big year, again unfortunately, for injuries to people in hospitals from doctors' and nurses' mistakes. And this is a special feature on this very human frailty, error.
We all make mistakes, but in some jobs, like piloting an aeroplane, or surgery, mistakes can be fatal; why do they occur? What’s going on in our heads and around us when disaster hits? In aviation, errors are accepted as inevitable, so planes and cockpit routines are designed to minimise the impact of mistakes when they occur.
Sadly, hospitals haven’t often learnt these lessons, which means that the human factors in health care have either been ignored, or seen as too hard to deal with. The result is unnecessary injuries to patients, unsafe systems with needless harm.
But slowly, human factors are being acknowledged, and that’s due in no small part to one of the gurus in this field, psychologist Jim Reason, who’s Emeritus Professor at the University of Manchester in the UK. He was in Australia, in Perth, earlier this year at the Annual Conference of the Royal Australasian College of Surgeons. He told me that his journey in this field started with his own error-prone absentmindedness. I asked him for examples.
Jim Reason: Goodness: getting into the bath with your socks on, saying ‘Thank you’ to a stamp machine, and on one occasion putting cat-meat into the teapot. So you begin to see the kinds of conditions that create it, where you have for examples two objects, like a teapot, and a cat’s bowl, which are for putting in, you just get the wrong ones in.
Norman Swan: And you collected those stories?
Jim Reason: I collected them from other people; people really quite enjoyed doing this, and I watched for example my wife on one occasion. She was making tea and she reached down not the caddy but the Nescafe jar, and she put three teaspoonsful of Nescafe, and then screwed up the jar and put it back. Now that’s pretty trivial, it’s just that it struck me that her hand knew what she was handling, in other words not the lid of the tea-caddy, which slid on and off, but a screw-top jar. And the whole pointer for my early interests, was that it tells you a great deal about how you control your automatic actions. You have an intention to act, which you then delegate to various routines, and if you don’t check on the progress at certain choice points, then there is a strong possibility that you’ll go trundling down the strong but wrong route, the one that you most usually, most familiarly, do.
Norman Swan: And did your earlier research tell you why people go down that track?
Jim Reason: There’s two parts to the answer. The first part is the conditions under which absentmindedness occur, tend to be first of all in very familiar, very routine settings. They involve preoccupation or distraction, so that your limited attentional capacity is tied down either by some worry or by something going on around you, and there’s almost always some change either in the plan or in the circumstances. So you might, for example, get up and say ‘I’m not going to put sugar on my cereal, I want to lose weight’, but of course unless you attend exactly at that moment when you pour out the cereal, you’ll put the sugar on. And similarly, we on one occasion swapped the knife and fork drawers around and it took us three or four months actually, to get back to a correct, error-free performance.
Norman Swan: Particularly absentminded family?
Jim Reason: Well, yes. I am the most absentminded person....
Norman Swan: And you found this problem of delegating the task right, but your brain unattending to it, is a common problem not just in health care but in industry?
Jim Reason: It’s a universal problem. Little slips of action like that can create big disasters. It’s the context that determines the disaster, and if you’re driving unusually a double-decker bus, and you usually drive a single-decker bus, and you come to a low bridge that you used to go under with your single-decker, then you sweep off the top of the bus and kill six passengers, I mean that’s a terrible consequence for a very obvious, very routine slip of habit. And if there’s a general rule of absentmindedness, it is under-specified. If you under-specify some action either because you’re inattentive or because you’ve forgotten something or you have insufficient knowledge, there are many ways in which you can under-specify the control of actions. But they always, nearly always default to that which has been familiar, that which has been routine, that which has been frequent in that context. [...]
Aviation has largely digested the truth that people are not infallible, that the humanity slice of the cheese has holes in it and to provide a safe industry, we need other slices which, even though they have their own holes, will avoid the likelihood of holes lining up.
The medical profession on the other hand has historically proceeded on the basis that doctors are infallible. There is no medical equivalent of investigative agencies like the NTSB - why would there be if no mistakes were ever made or (as cynics observe) doctors simply bury their mistakes.
But in truth doctors are just as fallible as airline pilots, maintenance engineers and air traffic controllers.
In 2007 Boston surgeon Atul Gawande explored what medicine was starting to learn from the airline industry, in
his New Yorker feature, "The Checklist". He reported how Johns Hopkins Hospital critical care specialist Peter Pronovost had developed a check list tackling the steps required to put a line into a patient's vein (either for injecting drugs or the like or to remove blood samples - in intensive care beds lines often need to be left in place for a number of days).
The list contained just five items and nurses were backed by the hospital administration to stop doctors who missed any of the steps:
[...] Pronovost and his colleagues monitored what happened for a year afterward. The results were so dramatic that they weren’t sure whether to believe them: the ten-day line-infection rate went from eleven per cent to zero. So they followed patients for fifteen more months. Only two line infections occurred during the entire period. They calculated that, in this one hospital, the checklist had prevented forty-three infections and eight deaths, and saved two million dollars in costs.
Pronovost recruited some more colleagues, and they made some more checklists. One aimed to insure that nurses observe patients for pain at least once every four hours and provide timely pain medication. This reduced the likelihood of a patient’s experiencing untreated pain from forty-one per cent to three per cent. They tested a checklist for patients on mechanical ventilation, making sure that, for instance, the head of each patient’s bed was propped up at least thirty degrees so that oral secretions couldn’t go into the windpipe, and antacid medication was given to prevent stomach ulcers. The proportion of patients who didn’t receive the recommended care dropped from seventy per cent to four per cent; the occurrence of pneumonias fell by a quarter; and twenty-one fewer patients died than in the previous year. The researchers found that simply having the doctors and nurses in the I.C.U. make their own checklists for what they thought should be done each day improved the consistency of care to the point that, within a few weeks, the average length of patient stay in intensive care dropped by half. [...]
What this shows is what skilled people fail to do if they depend simply on their skill. (Along the way, Gawande tells of how development of checklists turned the Boeing B17, the Flying Fortress, from a plane that was literally unflyable to an aircraft so successful that 13,000 were eventually built.) The
New Yorker article was the basis for Gawande's recent best-selling book,
The Checklist Manifesto.
Bottom line: nobody, but
nobody, is infallible.