Patient Safety Tip of the Week


July 7, 2009     Nudge: Small Changes, Big Impacts





Yes, another holiday weekend means you get another book review! “Nudge” by Richard Thaler and Cass Sunstein is a book you’ve probably heard about on shows like Good Morning America. It’s the one that leads in with the story about how painting a picture of a fly in a male urinal resulted in 80% decreased spillage!


The theme obviously is that small changes which cost little or nothing (i.e. nudges) can result in big impacts. The book is full of examples of how nudges can help steer people to make better choices in their personal life (savings, investments, healthcare, etc.) or from a societal perspective (improve the environment, improve organ donations, etc.).


But the book is really about the way we think. It tells about our biases and how to recognize them and actually use them to “nudge” someone to do the right thing. There are certainly plenty of opportunities in healthcare to “nudge” people to do the right thing without interfering the their independence or ability to make choices. The latter point is one they stress over and over by defending what they call “libertarian paternalism”. Essentially that is the concept of promoting free choice but exerting the nudges to help people make those choices that most likely to be helpful. (They do, also, acknowledge numerous circumstances where less “paternal” parties might exploit those same biases to help people make choices that are not personally in their best interests.).


There are three closely related biases that are very common in everyday life: the inertia bias, the status quo bias, and the default bias. The inertia bias means that when faced with a difficult decision, we often do nothing. The status quo bias means that when presented with various choices, we often just stick with whatever we were previously doing. And the default bias, means we often stick with whatever choice is presented as the “default” option. Thaler & Sunstein emphasize the powerful nature of these biases but demonstrate how those biases can be utilized constructively. (Note they can also be used non-constructively such as when magazine companies require you to actively cancel a subscription or else you continue to pay for a subscription even though you may no longer read it!).


An example they give is employers providing health insurance for their employees. If employers simply asked annually “what health plan option do you want?”, many employees would simply procrastinate and perhaps suffer a lapse in coverage. So, instead, we offer the options with the “default” option being to continue the coverage the employee chose last year. Note that not changing might not be the best option for the employee but it is better than losing your coverage due to inertia. In many other circumstances, though, the “default” choice should not be the “status quo” option.


In healthcare we now often use the default option to facilitate best practices. Many patients who should get flu vaccinations never get them because they were not offered the opportunity at the appropriate time. Often they have actually accessed the healthcare system during the proper timeframe but no one remembered to offer them the flu shot. So now in our hospitals and offices we have adopted standing orders that say “if the patient meets the following indications and have none of the following contraindications, nursing staff should offer the patient the flu shot”. So the default option is the flu shot is offered.


Those of us who are involved in CPOE (computerized physician order entry) or designing standardized order sets understand the importance of well-designed forms with well-planned default options.


Thaler & Sunstein note that nudges work best for decisions that:

1.      Are difficult

2.      Lack immediate feedback

3.      Are not easily translatable into understandable terms


The immediate feedback is an important point. We stumbled onto an interesting example earlier this year on our way to discuss root cause analysis at a conference. On the highway that day there were multiple construction projects and we happened to notice the relative effectiveness of various ways of getting drivers to slow down. When drivers saw a sign that said “Speed Zone Ahead” or “Construction Zone Ahead – Speed Limit 55”, almost no drivers slowed down. When they saw the sign “Fines Doubled for Speeding Violations in Construction Zones” a few drivers slowed down. However, when they saw a radar-equipped sign that told them their own actual speed, a substantial number slowed down. That sort of immediate feedback was very powerful. Even better, if they saw a police car parked at the start of the construction zone or saw a worker holding a large reversible “Stop/Proceed” sign, they all slowed down. We actually took photographs of all these and now use them as analogies when we are showing the relative effectiveness of corrective actions proposed in root cause analyses! For example, education or training is simply a “Speed Zone Ahead” action (i.e. not very effective), but use of a checklist is the equivalent of the “Your speed is…” sign, and a forcing function or physical constraint is the equivalent of the “police car”.


Many times the benefit of a choice is not immediate but rather delayed or long-term. Obviously for many health benefits, preventive care (such as taking antihypertensive or lipid-lowering medications) has a positive impact many years down the road, not immediately. Mammography is also a good example. Most women who should get a mammogram know they should get it. But inertia and/or some other barriers often result in failure to get the mammograms. If a physician simply tells the patient they need one and hands them a prescription or requisition to get one, many women never follow up. If you can actually schedule the mammogram while the patient is still in your office, you substantially increase the likelihood she will get it done. And if you system can provide transportation for those who need it, compliance goes up even further. Best yet, if you can say “we can do it this morning” it is very likely to get done.


The above example demonstrates overcoming inertia bias by focusing on “channel factors”. The “channel factors” concept uses the flowing stream analogy to focus on how removing small barriers that impede the flow of the stream may facilitate flow in the desired direction. A good example Thaler & Sunstein give was an experiment done on Yale college seniors who where told they should get a tetanus shot at the college health center. Despite the fact that most understood the importance and said they would get the tetanus shot, only 3% actually got it. However, in a subset who received a campus map with the health center circled and were asked to look at their schedules, make a plan and devise a route to the health center, 28% got the tetanus shot!


Another example of a nudge in healthcare relates to flu vaccinations for healthcare workers (HCW’s). CDC and multiple other bodies recommend that all HCW’s get vaccinated against influenza to prevent transmission to vulnerable patients. If you simply tell employees they should get vaccinated, most don’t get vaccinated. So we have to remove “channel factors” and other barriers. So we make the vaccination free to them and provide it when they are already working at the hospital/office. We, of course, must provide them with informed consent, telling them both the potential benefits and risks of the vaccination. We’ve seen some informed consent forms that are so one-sided (telling them exclusively why they should get it but totally omitting risks) that they get suspicious and choose not to get vaccinated. Particularly if your HCW’s have the perception that their colleagues are not getting vaccinated, they are likely to refuse as well. Thaler & Sunstein really stress the importance of “social nudges” which stresses peer pressure and the fact that humans “like to conform”. So if you can show your workers that their colleagues are, indeed, getting vaccinated (like a sign on the wall stating “last year 97% of our staff got vaccinated !) you substantially improve the likelihood they will get vaccinated.


Note that the “smiley” emoticon above is actually a nudge factor. In their book, Thaler & Sunstein describe an energy company that provides feedback to their users about their energy consumption. After viewing their own consumption, users who were above the average usage tended to reduce their consumption and those who were below the average consumption tended to increase their consumption (we suspect some of this was simply regression to the mean). But interestingly, if the smiley emoticon accompanied the ranking showing a user was consuming below the average, they continued to be low consumers!


Thaler & Sunstein summarize the wealth of experimental literature that documents how powerful the tendency for humans to conform is. But some of you out there are ready to jump up and say “not my medical staff!”. But it is interesting that even rugged individualists and nonconformists may conform to some of their own “nonconforming” ideals. Thaler & Sunstein give a description of the “Don’t Mess With Texas” campaign. This began with an attempt to reduce highway littering in Texas. They knew that most of the litter was produced by males between the ages of 18 and 24 and that they were unlikely to heed a gentle warning “don’t litter”. So they developed a campaign where popular Dallas Cowboys players did spot ads, picking up litter and crushing beer cans while growling toughly “Don’t Mess With Texas!”. Not only did that become the most popular slogan in Texas and the whole US and spawned sales of mugs, tee shirts and hats with the slogan emblazoned on them (we actually saw one this weekend miles 1650 miles north of Dallas!) but it resulted in a reduction of roadside litter by 72%!!!


Another nudge factor is ‘priming”. That means getting an issue into someone’s attention. A form of “priming” is the “mere-measurement” factor. If you ask potential voters whether they intend to vote, their likelihood of actually voting increases by up to 25%! We wonder if “Do you intend to wash your hands?” would get that sort of response. We think you have to add lots of channel factors to make that one work. A better example of priming is presentation on standardized order sets (either paper or CPOE) of a place to indicate whether DVT prophylaxis is to be used. Just doing this increases the likelihood that DVT prophylaxis will be used. We can also remove some channel barriers by offering the various options for DVT prophylaxis, perhaps pre-selecting a default option based on the type of patient.


Another concept important in nudges is “salience”. Salience means that some aspect is clear and understandable. Thaler & Sunstein provide as an example the EPA mileage example on new cars as changing from a mileage range to a predicted “dollars saved in fuel consumption”. In healthcare, an example might be a CPOE screen on a pneumonia patient. Instead of asking “is this a high risk patient?”, we might actually present the physician with a risk calculator such as the Pneumonia Severity Index (PSI) or the CURB-65 tool, which might help them decide whether the patient needs hospitalization or could be treated as an outpatient or whether ICU admission should be considered.



“Nudge” is a good read. It is one of the contemporary psychosocial books of the type you’d expect from a Don Norman (see our November 6, 2007 Patient Safety Tip of the Week “Don Norman Does It Again!”) or Malcolm Gladwell (see our May 29, 2007 Patient Safety Tip of the Week “Read Anything & Everything Written by Malcolm Gladwell!” that are both easy to read and full of practical advice that you can relate to. This book has lots of examples you can use in your personal and professional life.





Thaler RH, Sunstein CR. Nudge. Improving Decisions About Health, Wealth, and Happiness. New Haven: Yale University Press, 2008.









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