I said Poka-yoke, not Pokemon: Where Checklist Manifestos and Japanese Manufacturing Meet Cataract Surgery

Have you ever taken a test and then gotten back the graded paper and discovered some incredibly careless mistake that you never thought you could possibly have made? It is amazing that even when we double check our answers, we still sometimes make those stupid, little errors: we add two key numbers instead of multiplying or we forget a word that renders our thesis statement incoherent to the outside world. My test-taking career has certainly been riddled by these kinds of errors, and what I have come to accept is that they are beyond prevention, unavoidable, a price of being a member of the species homo sapiens.

Medicine is not immune to human error. In fact, the procedures and practice of medicine are so complicated that the likelihood of making an error may be much higher than a stupid mistake on a three-page written exam. And, worse still, the price that is paid for those errors is exponentially higher. A doctor forgetting to wash his hands can be the difference between sending an inpatient home safely the day after a procedure and an extended stay in the inpatient ward with a potentially life-threatening hospital-acquired infection. It’s hard to really appreciate the chance of a medical error or the costs that medical errors exact without some context. 403 people across the world died in plane crashes in 2012, just over 30,000 people died in the US in car accidents in the same year, and it is estimated that over 200,000 in the US died from preventable medical errors in 2012 (Journal of Patient Safety: http://journals.lww.com/journalpatientsafety/Fulltext/2013/09000/A_New,_Evidence_based_Estimate_of_Patient_Harms.2.aspx). Why do so many medical errors occur? The explanation probably has to do with systemic problems and challenges in medical care; it’s not about a few bad doctors/nurses. Medical care is really hard to do properly, and there are just failings in the system that put patients at risk.

At Aravind Eye Care Systems, there have been extensive measures taken to refine the system to prevent medical errors. As a result, the rates of complications in procedures and hospital-acquired infections are extremely low and well below national and international averages; Aravind surgical complication rates are less than half those seen in the UK.

A figure from the consulting giant, Mckinsey & Company:

Screen Shot 2015-07-01 at 12.53.05 AM copy

However, the problem that Aravind runs into is a sort of law of large numbers. There are huge patient volumes at Aravind, and the way that patient flow is designed, patients are interacting with many, many people in a single visit. In one out-patient visit, there may be as many as 15 patient interactions with Aravind staff, and there are even more during an inpatient admission. This means that in a typical, single day, when Aravind is seeing well over 2000 patients, there can be as many as 50,000 interactions with patients. So even if the chance of an error is 0.0001% per interaction, with this many patient interactions, there are still bound to be a non-trivial number of medical errors. And this is something that the Chairman of the Hospital, Dr. R.D. Ravindran (aka Dr. RDR), is dogmatic about. To him, having a low rate of errors is not enough; one medical error that harms a patient is too many. A 0% rate of medical errors is the only acceptable value.

One of my projects for the summer is to work on the issue of patient safety to try to prevent medical errors. In part, this involves putting together a patient safety manual for staff along with posters and presentations that include comprehensive protocols for all procedures in the hospital. At another level, though, I am trying to find little ideas for small process changes that can be done to make procedures a little safer. To that end, I have been reading a lot about checklists.

The checklist is not a novel concept, and yet a checklist was probably one of the most significant, life-saving medical innovations in the last fifteen years. In the early 2000’s, Peter Pronovost, an ICU doctor at Johns Hopkins, started to find that steps in the official, standard procedural protocols were often being skipped (inadvertently) by nurses and doctors. So he pushed people in his ICU to use a short checklist when inserting central venous catheters. The result he found was that just the simple checklist could greatly reduce the number of hospital-acquired infections. In a large study of Michigan hospitals that was published in 2003 in the New England Journal of Medicine, it was discovered that installation of Pronovost’s checklist approach reduced infection rates in ICUs by 66% and saved as many as 1500 lives (http://www.nejm.org/doi/full/10.1056/NEJMoa061115). The success of the initiative partially inspired the famous public health researcher and New Yorker staff-writer, Atul Gawande, to write a book called the Checklist Manifesto: How to Get Things Right, in which he promoted the use of checklists in surgery and beyond (here’s a link to an article Gawande wrote in 2007 about the Pronovost checklist: http://www.newyorker.com/magazine/2007/12/10/the-checklist).

Aravind has a very simple checklist for eye procedures; it involves the surgeon and operating theatre team signing off on the fact that they have confirmed the patient identity, the site of surgery, the procedure to be done, and the type of intraocular lens to be inserted in the case of a cataract procedure. The checklist seems to work quite well, but I am obsessed (probably to the annoyance of Olivia and Busra, at whom I throw my wacky ideas all the time) with trying to see if there are some ways to supercharge it because even in spite of the checklist, mistakes are still being made. One idea is to have more people (in particular, those who interact with the patient prior to the operation theatre) fill out a checklist. Even though, these individuals are supposed to already be doing checks, filling out a checklist may reduce the likelihood of a nurse or a physician forgetting to ask about something or forgetting to check something. It would in essence be like running a check on the check that is already being done by the operating team, or in other words, like doing a triple- or quadruple-check of your answer on an exam.

Yesterday, though, I was sitting in the patient care office of the outpatient hospital, and I got to talking to an engineer, who worked at Coca Cola as a manager of operations, but who was in the process of resigning from Coke to start a robotics start-up targeted at the health care industry. He had come to Aravind to see how robotics technology could be used in the hospital. After telling him a little bit about the patient safety project and my ideas with beefing up the checklist, he suggested that I shouldn’t be looking for more checks. He said I should be thinking about a Japanese technique called “poka-yoke,” which in English means “mistake-proofing.” It is a strategy that Coke and other manufacturers use on the manufacturing line to prevent human error from even coming into the equation, and it involves using automation to eliminate unnecessary human discretion or make it incredibly obvious when an error is being made. The analogy here would be that if you were worried about people making small, stupid mistakes in an answer to a test question, don’t just force them to check the answer, turn the question from free response into multiple choice. Eliminate the possibility of little mistakes.

In the few minutes of talking to him alone, I think that I came up with one idea where mistake-proofing can be used in the hospital. One of the medical errors that Aravind is desperately trying to completely eliminate involves operating or doing something at the wrong site (i.e. the wrong eye). There are a couple of checks and tricks that are used to prevent a mistake like this. There’s the checklist, but there are also others: a patient identification wrist-band is placed on the hand corresponding to the eye of the operation, a bright sticker designating the target eye is placed on the patient’s case folder, and a small mark is made above the temple of the target eye to basically give the surgeon and anesthesiologist a bull’s-eye target (most surgeries here use local anesthesia, so the anesthesiologist anesthetizes the eye to be operated upon and is very much implicated in targeting the correct eye). Even in spite of these little checks, there are a number of cases each year where the wrong eye was anesthetized or even operated upon, and in more than half of these cases, everything, including the wristband, the sticker, and the marking, was done correctly. These so-called “acute” cases are very mysterious, but they can happen because a doctor didn’t realize which side of the bed he or she was standing on, or had already done so many in a day that he/she momentarily lost focus. I think that these acute cases can be totally eliminated with a little poka-yoke. What if at the time that the temple is marked in the inpatient ward, a patch is put over the eye not being operated upon. Then, not only is the target for the surgery marked on the correct eye, but the possibility of doing something inadvertently to the other eye has been literally blocked with a piece of cloth. Not only is the test question multiple choice, the wrong answer has already been scratched out.

Maybe mistake-proofing like this is so simple that it can’t solve larger cultural weaknesses in the Aravind system for patient safety. Maybe even beefing up the checklist isn’t particularly relevant to reducing medical errors. But maybe, just maybe, we can prevent a mistake.

4 thoughts on “I said Poka-yoke, not Pokemon: Where Checklist Manifestos and Japanese Manufacturing Meet Cataract Surgery

  1. Hi Vivek:
    Great work and logical writing; your focus on excelling and doing good are so apparent in this blog.
    Congratulations to you and all the other CASI interns in India; I have learned a lot from everybody’s keen observations and enthusiastic, helpful and fun approach to adventure. Wish you all a safe journey back home.


    1. Hi Shobana,
      Thanks for reading our blogs! And thanks so much for the kind words and support! I really hope that I am able to turn wanting to do good into something that can be implemented and actually has a real impact. I guess the brief epilogue to today’s blog is that my supervisor for the project was not quite as convinced that mistake-proofing is the way to go, but hopefully, I will either be able to convince her over time or find some better ideas for patient safety in the very real possibility that I have no idea what I am talking about haha. But regardless, I am a learning a ton through it all, and I am so lucky to be here. Hope you are having a wonderful summer!

      1. Your ideas for mistake proofing will somehow affect the patient safety process, perhaps another staff member/doctor could be more open to new ideas. As you may have noticed, change does happen a bit slowly in India. Will you write a summary of your observations? If so, a few copies given to other section head honchos may help.
        My husband is a prof at UPenn and he and his colleagues are always looking for good ideas from students and lab members esp. where bio safety is concerned.


      2. Hi Shobana,
        I have shared some ideas with another supervisor as well, and I am going to try to write up my thoughts to share them more formally with my supervisors. I also feel that there is a fair chance that I am not quite correct or not fully grasping what is going on, and so I am reluctant to be too self-assured. But I would certainly love to share my ideas with you and your husband if the two of you would be interested! If you let me know of your email here, I can pass along whatever I come up with- or if you would prefer to send your email address to me via email, my email address is vivekn@wharton.upenn.edu (though also please feel no pressure whatsoever to follow-up and read more stuff from me!).
        All the best,

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About Vivek Nimgaonkar

Rising Senior in the Roy and Diana Vagelos Life Sciences and management Dual Degree program, majoring in Biology and concentrating in BEPP and HCMG at Wharton. Intern at Aravind Eye Care Systems in Madurai Tamil Nadu for summer 2015.