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When “nudge” doesn’t work: Medication Reminders to Outcomes After Myocardial Infarction

Gur Huberman points to this news article by Aaron Carroll, “Don’t Nudge Me: The Limits of Behavioral Economics in Medicine,” which reports on a recent study by Kevin Volpp et al. that set out “to determine whether a system of medication reminders using financial incentives and social support delays subsequent vascular events in patients following AMI compared with usual care”—and found no effect:

A compound intervention integrating wireless pill bottles, lottery-based incentives, and social support did not significantly improve medication adherence or vascular readmission outcomes for AMI survivors.

That said, there were some observed differences between the two groups, most notably:

Mean (SD) medication adherence did not differ between control (0.42 [0.39]) and intervention (0.46 [0.39]) (difference, 0.04; 95% CI, −0.01 to 0.09; P = .10).

An increase in adherence from 42% to 46% ain’t nothing, but, yes, a null effect is also within the margin of error. And, in any case, 46% adherence is not so impressive.

Here’s Carroll:

A thorough review published in The New England Journal of Medicine about a decade ago estimated that up to two-thirds of medication-related hospital admissions in the United States were because of noncompliance . . . To address the issue, researchers have been trying various strategies . . . So far, there hasn’t been much progress. . . . A more recent Cochrane review concluded that “current methods of improving medication adherence for chronic health problems are mostly complex and not very effective.” . . .

He then describes the Volpp et al. study quoted above:

Researchers randomly assigned more than 1,500 people to one of two groups. All had recently had heart attacks. One group received the usual care. The other received special electronic pill bottles that monitored patients’ use of medication. . . .


Those patients who took their drugs were entered into a lottery in which they had a 20 percent chance to receive $5 and a 1 percent chance to win $50 every day for a year.

That’s not all. The lottery group members could also sign up to have a friend or family member automatically be notified if they didn’t take their pills so that they could receive social support. They were given access to special social work resources. There was even a staff engagement adviser whose specific duty was providing close monitoring and feedback, and who would remind patients about the importance of adherence.

But, Carroll writes:

The time to first hospitalization for a cardiovascular problem or death was the same between the two groups. The time to any hospitalization and the total number of hospitalizations were the same. So were the medical costs. Even medication adherence — the process measure that might influence these outcomes — was no different between the two groups.

This is not correct. There were, in fact, differences. But, yes, the differences were not statistically significant and it looks like differences of that size could’ve occurred by chance alone. So we can say that the treatment had no clear or large apparent effects.

Carroll also writes:

Maybe financial incentives, and behavioral economics in general, work better in public health than in more direct health care.

I have no idea why he is saying this. Also it’s not clear to me how he distinguishes “public health” from “direct health care.” He mentions weight loss and smoking cessation but these seem to blur the boundary, as they’re public health issues that are often addressed by health care providers.

Anyway, my point here is not to criticize Carroll. It’s an interesting topic. My quick thought on why nudges seem so ineffective here is that people must have good reasons for not complying—or they must think they have good reasons. After all, complying would seem to be a good idea, and it’s close to effortless, no? So if the baseline rate of compliance is really only 40%, maybe it would take a lot to convince those other 60% to change their behaviors.

It’s similar to the difficulty of losing weight or quitting smoking. It’s not that it’s so inherently hard to lose weight or to quit smoking; it’s that people who can easily lose weight or quit smoking have already done so, and it’s the tough cases that remain. Similarly, the people for whom it’s easy to convince to comply . . . they’re already complying with the treatment. The noncompliers are a tougher nut to crack.


  1. Dale Lehman says:

    I have not read the study, so there may well be more important details regarding what the specific treatments were that either were or were not complied with. But the general statement that compliance is “close to effortless” may be wrong. Many of the treatments have nontrivial side effects and this can be a major reason for noncompliance. So, an important thing to explore would be whether the compliance rates differ across treatments and/or particular subgroups. Hopefully the paper explores this.

    • David L. says:

      “But the general statement that compliance is “close to effortless” may be wrong.”

      That was my thought, too. My experience is that it’s really really easy to forget to take one’s meds. One gets involved in a book/project/phone call or whatever and the pills are gone from one’s consciousness. I think most people grossly underestimate how hard it is to take a stupid pill once every 4 hours. Make that three meds on different schedules, and it’s almost impossible.

      That the problem of _remembering_ to take one’s pills can’t be fixed by “nudges” shouldn’t surprise anyone. It’s not a matter of motivation, it’s a matter of how human memory works. If there’s something on my mind, or something of interest comes up, it chases everything else away to oblivion. So it’s no surprise that I often can’t remember whether or not I’ve taken my after the last meal pill. (I’ll often count the remaining pills to see if I’ve forgotten.)

      I wonder if a cell phone app would help? My bet is that what you’d see is people telling it that they’d taken their pill (with the full intention of taking said pill) to shut the app up and then forgetting the pill anyway when they go back to what they were doing when the app interrupted them. Like I said, taking meds on a schedule is essentially impossible.

  2. Tim Josling says:

    > doesn’t work

    > did not differ

    > P = .10

    Write out 1,000 times:

    “Just because the P value fell (slightly)above the arbitrary standard of 5%, this does not show there was no effect; indeed it shows that the effect size seen was not likely if there were no effect”.

    > significantly

    Significance is an attribute of the study not of the effect.

    inb4 teaching your grandmother how to suck eggs.

  3. Jonathan says:

    I think it’s a failure of the rationality model which fails to understand the actual complexities of human responses. Example: when you meet cancer patients, you find many continue bad habits, like smoking and drinking, that actually compromise their life expectancies. This is true even if they have families that depend on their continued existence. Why? Self-hatred is complicated. Not feeling that your life is entirely worth saving is complicated. Feeling victimized is complicated and being ill causes changes in your mental outlook, particularly in how you see whatever future you may have. Many patients are so afraid that they keep one foot in non-compliance and one foot in compliance, partly because they fear that if they put everything into treatment and that fails then they’ve been rejected by life, by God, by themselves. Many also fear being heathy because they know their faults and often feel they don’t truly deserve health, and then they may be crippled as well by the fear that illness may come back and that, they fear, will crush them.

    This is true of smokers generally: they exchange short term versus long term every single time they light up, so why would people that they have short term fears and other issues that press them into short term decisions that conflict with what others perceive as the best long term choices and goals?

    The concept that adherence to a regimen is easy is absurd. As perspective, I’m in ridiculously good physical condition. I take 3 or 4 stairs at a time. I am strong and lean. And I know how much effort that takes. I enjoy the effort but it’s a common subject among the relatively few people like me that most people can’t get to anywhere near enjoying effort enough to get physically healthy, except perhaps in bursts of energy. Even when told ‘it’s the same as doing anything else you enjoy where you need to learn and you like the work’, only small handfuls can figure out how to make physical work, and the pain that entails, into fun, though it is. Many people I know have trouble adhering to any regimen other than getting up and going to work. Here’s a simple question: how often do you sharpen the knives in your house? Most people probably never. It takes 5 minutes to do a basic sharpening and honing of every knife I have once a week. That’s a regimen. How many people do you know who keep to any such regimens? Look at obesity.

    Add to this that huge numbers of people are depressed. Many would qualify as clinically depressed, whatever that means, but huge numbers are generally ‘down’. Add in an illness and the mood drops even more. This is especially true with older people, by which I mean anyone 45 to 50 and older, because they refuse to accept that they are depressed. And that becomes more and more true as they get older and sicker. Life has a way of adding up and many people believe that what has added up is what they deserve and they don’t realize it’s their mood and general unhappiness speaking.

    One can say the people who are ready to get fit are fit, but that kind of misses the point of trying to figure out how to get more to be ready to get fit. My problems with ‘nudges’ can be classed in two categories. First, the connection is not generally meaningful, either because the stakes are low or the cost/benefit is remote from the short-term mentality (see smokers). Second, the concept is based on a version of rational behavior that in this context is less reliable than generally because this isn’t a market but the reduction of rational models to a single point, meaning to a person. That’s why I expect small to noisy results: the forces that impose don’t generate a value that is shared, like the price of a cookie, but is expressed entirely within a human being and that person’s actual choices. If I want a cookie, I’ll pay the price because that’s the market and they sell a certain number of cookies based on how they look, the cost, the taste expectations, etc. But if I want to get better, there is no market for that. The studies accumulate not the factors that generate a price for a cookie – or its quality versus other cookies in the market – but what’s inside the person. I’d say that takes the model level of a cookie and misinterprets it to represent the reduction to the desire for a cookie within each individual. Imagine that all the customers are patients: some will want to buy that cookie and some won’t. That’s more the reality because that models what’s inside people not how externalities govern aggregate behaviors. I think of it as the difference between the cost of something and the cost within you. Cigarette packaging has worked on this level with the warnings intended to convey to the person the cost of this choice in non-monetary terms. Think about the relationship between cost versus warnings as limiting smoking, when that’s something you know may kill you, and then try to translate that into ‘you should do this because it’s good for you’. They don’t translate easily.

    Sorry for the long comment. I try to be at least a bit interesting.

    • jim says:

      I smoked for almost 30 years. I tried to quit almost every year. It’s not about self hatred, snort. It’s extremely addictive.

      Re People not taking meds: This is why the public shouldn’t be forced to pay for universal universal health care – because what people dont pay for themselves they don’t care about, so they waste it.

      • Daniel H. says:

        Hey Jim,
        not trying to start an offtopic discussion here, but there may be very rational reasons for universal health care, e.g. efficiency (costs per patient). To turn this into a Bayesian argument, this might be a topic where we should all avoid having very strong prior beliefs.
        Cheers, Daniel

      • Joshua Pritikin says:

        I don’t think that would be the main effect of universal health care. What I would expect is that universal health care would put much more focus on preventive treatment as opposed to maximizing procedures and selling drugs. Plant-based nutrition could eradicate heart disease. We’ve known this for decades, but prevention isn’t good for profits so there is little interest in diet and lifestyle from doctors or professional organizations.

  4. Anonymous says:

    After reading the title of the news article mentioned in the beginning of this blog post, all i can think of now is that i feel there need to be t-shirts with the text “Don’t nudge me bro” printed on it.

  5. Daniel H. says:

    ” There were, in fact, differences. But, yes, the differences were not statistically significant and it looks like differences of that size could’ve occurred by chance alone.”
    Maybe it’s enough that the possible gain is not practically significant. This made me think about whether practical thresholds like “required effect for a reasonable costeffectiveness” would be a better target for power calculations than biased estimates from the literature. If there is a real effect, but too small to be of practical use, why bother?

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