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There’s something special about Fridays, and in the summer, we seem to feel it even more.

As I’ve talked about before on the show, there’s also something about Fridays at the U.S. Food and Drug Administration, or F.D.A. Research published in 2020 looked at what happens when the F.D.A. issues drug safety alerts on a Friday, compared to any other day of the week. It was an eye-opening study that we talked about previously on the show, and we’re going to replay that episode for you today. So, now you have a little something to contemplate as we head into a longer weekend, and as summer itself winds down.

As you’ll hear, my guests Ben Barber and Luis Diestre found that when the F.D.A. issued drug safety alerts on Fridays, these important updates got less attention. I wondered at the time what impact simply moving these alerts to another day of the week could have in terms of that information gaining more traction. We followed up with the F.D.A. and they couldn’t confirm if they stopped releasing alerts on certain days. But a glance at their safety alerts website indicates that these alerts are still released on Fridays. So, there hasn’t been any change as a result of Ben and Luis’s work.

Maybe that’ll change with the rebroadcast of episode number nine, “Why Fridays May Be Dangerous for Your Health.”

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All day long, for reasons big and small, we hear and feel and see alerts. Things that need our attention. It could be work-related …

Or personal, like a happy birthday text from a college roommate …

Or maybe a breaking news alert …

These alerts are the soundtrack to our lives right now. And by the end of a long week, I’m ready to unplug and ignore all the alerts. And that’s one reason why we all love Fridays. Personally, I try to spend less time in front of the computer, I tend to check out a little bit early. I get on the soccer field if I can. Of course, it’s also movie night with the kids. Turns out, though, I’m not alone. There’s actually something called the Friday Effect. Just ask economist Benjamin Barber.

BARBER: Every time something happens on Fridays, I’m always like, oh, it’s the Friday Effect. I always think, “Oh, I shouldn’t send an email on Fridays because the odds are, they’re not going to get it or they’re going to wait. Friday, I don’t try to bother anybody if I really want something done. Unless Luis, right? Luis is going to be all on it.”

Luis DIESTRE: My name is Luis Diestre. So, in my case on Fridays these are the days where I work the most, especially after publishing this piece.

You might be wondering why Luis works so much on Fridays. Well, he, Ben Barber, and Juan Santaló are researchers and professors at I.E. Business School in Madrid, Spain. And not long ago, they wondered if, for a very curious reason, Fridays could be dangerous for our health.

From the Freakonomics Radio Network, this is Freakonomics, M.D. I’m Bapu Jena. I’m an economist and I’m also a medical doctor. Each episode, I dissect an interesting question at the sweet spot between health and economics. Today, we’re going to talk about drug safety alerts: what they are, who they’re for, and why the Friday Effect matters.

Ben Barber and his colleagues were inspired to take a closer look at public health alerts that are released on Friday afternoons because of an episode of the old N.B.C. show set inside a fictional White House: The West Wing.

BARBER: I don’t know if you’re familiar with the West Wing, but they have this, show take out the trash day.

DONNA: What’s take out the trash day?

JOSH: Friday.

DONNA: I mean what is it?

JOSH Any stories we have to give the press that we’re not wild about we give all in a lump on Friday.

DONNA: Why do you do it on Friday?

JOSH: Because no one reads the paper on Saturday.

DONNA: You guys are real populists, aren’t you?

This “Take out the trash” idea on The West Wing is ripped from the real world. Folks listening who work in finance or media might already know this well. It’s when companies and even governments take advantage of our inattention and release reports and news on Fridays that they’d rather we didn’t pay much attention to. The goal is to avoid unflattering media coverage. For example, any story that might negatively impact a company’s stock price.

But, could something as important as drug safety alerts be a victim of the Friday Effect? Researcher Luis Diestre started crunching the numbers.

DIESTRE: I was trying to check the days of the week in which these alerts were released, and I came across a very suspicious pattern. We saw that Fridays were overrepresented, right? So, alerts were more likely to happen on Friday than any other day of the week.

In the U.S., drug safety alerts to the public come from the Food and Drug Administration; or F.D.A. One of the F.D.A.’s jobs is to continually collect data about the side effects of drugs that the F.D.A. has approved. The F.D.A. also has a drug oversight board that evaluates that information. And if they believe there’s enough evidence that suggests a certain adverse effect, maybe of the drug itself, maybe of an interaction to watch out for between other drugs, then they release a safety alert to the public.

In those alerts, they explain the issue and provide recommendations, like changing the dose or maybe stopping the medication altogether.

There are a few ways these safety alerts get communicated to the medical community and the public. For example, drug companies and sales representatives can share safety information with medical professionals. Electronic Prescribing Systems that healthcare providers use often get updated with safely alert information too. So, when a healthcare provider punches a prescription into the system, they’ll see any alerts relating to the drugs.

The F.D.A. also provides information on all new drug safety alerts directly to the public: on their MedWatch website, through Twitter, and by email. News organizations sometimes pick up these safety alerts too. So, the information is available. But it’s in noisy, crowded places. And Luis says it’s hard for the people who need the alerts to wade through all of the details.

DIESTRE: We know that not every doctor follows the F.D.A. Not every doctor is subscribed to the email subscription service or follows the MedWatch Twitter account.

Luis and Ben wanted to measure how much attention a drug safety alert gets. Not every doctor is on Twitter, at least not before the pandemic, and not every doctor follows the F.D.A.’s MedWatch account either. So, they looked at more traditional media coverage of safety alerts too.

BARBER: We can look at news articles that sort of pick up these safety alerts. And then we try to look at what the effects would be, given that it was on a Friday versus other days. Lo and behold, what we find is that Fridays — these news organizations and people on Twitter pick these things up less.

First, their research found that alerts were more likely to be communicated on a Friday than any other day of the week. They also found that alerts released on a Friday were shared 34 percent less on social media and were 12 to 51 percent less likely to receive news coverage. And that led to another question, where the stakes were pretty high:

DIESTRE: If people are paying less attention to these events, maybe these could have implications on public health.

And that’s what they found. If the safety alert was published on any other weekday, it reduced drug-related deaths by 22-36 percent compared to if the safety alert was published on a Friday. Luis was stunned by the findings.

DIESTRE: I remember pushing ourselves to try to break the results. There was no way to break them. One of the strongest results I’ve ever seen in my career as a researcher. So, we were strongly surprised about the magnitude of this effect, because what you find is that Friday alerts are almost ineffective the first six months. So, it’s a very dramatic and very strong effect.

I want to emphasize what Luis just said: if a drug safety alert comes out on a Friday, it isn’t just that the alert doesn’t get much attention over the weekend, but everyone catches up and knows about the safety alert just a few days later. It turns out that the information actually gets ignored on a Friday, and the net effect is that it takes MONTHS longer for the information to disseminate to healthcare professionals and the public. Ben was so surprised that they took extra care to double check the findings.

BARBER: As a researcher who does a lot of empirics, you know, you can always find results, but they could be spurious. You want to make sure that it’s both substantively significant and also statistically significant. I wasn’t necessarily shocked it was statistically significant, but I was shocked at how large the magnitude of the effect was. I was not expecting how dramatic it would be in terms of public health. I did not think that it would lead to more deaths, lead to more serious injuries, or lead to more side effects in general.

Coming up, we hear about how the Friday Effect plays out on the front lines of medicine. And more with Ben and Luis about who could fix this problem, and how. I’m Bapu Jena and this is Freakonomics, M.D.

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After seeing the strength of the Friday Effect, my guests Ben Barber and Luis Diestre wondered: who, or what, might be influencing the F.D.A.’s decisions on when an alert comes out?

BARBER: We had thought ahead of time maybe it’s the firms who are lobbying the F.D.A. In the paper we have this histogram, which shows that, for non-lobbying firms, you essentially have this flat line of almost any day of the week is equally likely to get a alert. Whereas for lobbying firms, it’s essentially, a third of them. And then eventually we started thinking about, well, what are the consequences of this, as Luis was pointing out. And we had a real aha moment when we realized, “Oh, wow, maybe this is actually having this public health issue where people aren’t getting the information they need.” And then it became a public service announcement of some sorts to try to say: “Hey, don’t release things on Fridays because people are going to get hurt.”

In medicine and healthcare policy, there usually aren’t quick fixes. But what drew me to Ben and Luis’ study is that the problem that they identified — people being less aware about drug safety alerts that are issued on Fridays — had a fix that was pretty simple. Just don’t send any drug safety alerts on Friday. Even waiting a few days, until the following Monday, could mean the alert is seen by a lot more people.

Ben and Luis have been shouting their findings from the rooftops because it seems like there actually could be a quick fix, in this case. They’re not doing the shouting on Fridays, of course. But so far, they haven’t gotten much feedback from either drug companies or from the F.D.A.

I reached out to the F.D.A. and they provided us with a statement saying, and I quote: they aim to issue drug safety alerts as soon as possible. They also said they have a number of mechanisms in place to amplify information beyond the initial alerts. They did, however, decline to respond to the specific findings of Ben and Luis’s research.

So, maybe this study could convince drug companies or the F.D.A. to change when they release drug safety alerts. That would be a great experiment. But it would only be the first step. Because knowing and acting aren’t the same thing.

Joseph ROSS: What we know from other studies that look at utilization is that these safety alerts or even more serious ones, like black box warnings, that are the changes to the drug label that are the most serious safety concerns, that they rarely lead to changes in prescribing. And they actually rarely lead to changes in insurance formulary coverage, which are both much more important measures of what actually happens in the world.

That’s Joe Ross. He’s a professor of medicine and public health at Yale University.

ROSS: We need to do a better job of communicating information to patients and to prescribers. When there are safety concerns identified, the F.D.A.’s distributed system of using social media and “Dear Doctor” letters and emails and the companies that do the same. As a practicing general internist, I can tell you. Those emails get deleted pretty quickly because it’s just a lot of noise. You don’t know how serious it is. Like, what is the likelihood of the risk? Practicing clinicians in particular rely on their peers along with guidances from professional organizations that are deliberately attempting to aggregate this information. And that can be communicated back to an individual physician or prescriber because there is too much noise out there. Someone has to do that job of aggregating. Ideally, it should be the F.D.A.

That might help medical professionals make sense of the barrage of information. But what about patients? Again, Ben Barber.

BARBER: The safety alerts themselves are fairly complicated. So, I don’t necessarily think that patients are going to be able to look at them. I’m not a doctor, I don’t know what all of these say and what they all mean either. What I’ve learned in this process is I should trust doctors more about these things and hope that they are up to date on this stuff.

Luis Diestre hopes the study makes it clear that the Friday Effect isn’t just about short-term stock market performance or avoiding headlines. And that realization could change the incentives for how regulators and drug makers behave.

DIESTRE: My feeling is that firms are not aware of the implications of getting alerts on Fridays. Maybe they think that this is beneficial for them because they somehow minimize the noise or the punishment in the stock market. But my feeling is that they’re not aware of the public health implications so maybe if they have that information, their incentive system will change because, of course, firms don’t want these public health consequences either, right? So, even for purely economic reasons.

Joe Ross says we need even bigger changes. Like taking a step back and rethinking how the F.D.A. collects data on safety information and then, how they release it to the public.

ROSS: This adverse event reporting system is just that very tip of the iceberg. We know it’s basically voluntary for patients and clinicians. It’s a burdensome system in which to submit. While it’s required for industry, there’s been other reports that show that they get delayed. They don’t always get reported. And, you know, even when you look at them, they’re very difficult to disentangle and to get at a relative risk as opposed to a number of events. You don’t know if that one adverse event that’s reported for that use of a drug was in one person who used the drug or in 1 million people who use the drug. And so, you just have no sense of, well, is this an important risk or is this just a random occurrence that took place? So, there’s much that we can do to advance F.D.A.’s regulated surveillance efforts. It’s not like if a safety warning comes out that the patients are automatically alerted, we don’t have systems in place to do that. The pharmacists actually do get the very same information and are much more attuned to new safety changes to drug labels and the “Dear Doctor” letters. Often, we are relying on the pharmacists in the community to alert the patients who then come and talk to the doctors about it.

Like Joe Ross is saying, regulators, drug companies, prescribers, pharmacists, and patients all have a role to play in making sure good information gets out and gets listened to. This study from Ben and Luis also reminds me of some research I did a while ago that looks at studies that, by chance, happened to be published around big, unexpected events. Like hurricanes, other natural disasters, mass shootings, et cetera. Those studies could, in theory, get less attention and have lower long-term scientific impact, simply because when those studies are released, people’s attention is elsewhere. But we actually didn’t see fewer citations of those studies in the future. So, it’s not that relative inattention to an issue, in this case to a new scientific study, always has long-term effects. But it can.

With most drug safety alerts, delaying a response by just over the weekend is unlikely to have any negative public health impact. In most cases, these are drugs people have been taking for a long time. And the real issue is identifying side effects that come from long-term use or new interactions with other drugs, as opposed to acute side effects that just happen overnight. In that instance, any hypothetical, trivial benefit that might come from patients not taking a drug over the first weekend the information is released is dwarfed by the benefit of people knowing more about the safety alert in the months ahead.

In medicine, lots of problems feel intractable and complex. Moving drug safety alerts around on the calendar by a few days to help make sure more people see them feels simple. Drug companies and the F.D.A. could give it a shot. I’d actually be really curious to see the data if that change was made. And I know Ben and Luis would be too. We’ll just have to keep a close eye out for it. Chances are though, the announcement would be made on a Friday afternoon.

Anyway, that’s it for this week’s episode of Freakonomics, M.D. I want to thank my guests, Ben Barber, Luis Diestre, and Joe Ross. And thanks to you for listening! As always, tell your friends about the show and let us know how things are going. I’m at bapu at freakonomics dot com.

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Coming up next week: We’re going to answer a question from a listener named Max.

MAX: Hey Bapu, this is Max. So, a few weeks ago, my father had a heart attack and triple bypass.

Because of what happened to his dad, now Max is concerned about his own heart health, and wants to know if he should get tested. But what do tests tell us? Is more information better? Is more testing better?

REDBERG: Somehow people have the idea that having a test could help you to live longer or to live better. And I don’t know of any tests that can do that,

We’re going to talk about testing in medicine, specifically in cardiology. Who needs a test, which test they need, and if these tests are actually helping doctors find and prevent heart disease.

YEH: If you did angiograms on everybody over the age of 60 or 70, you’re going to find a large number of people with these 30, 40 percent blockages that may never actually affect the patient in any way.

That’s all coming up next week on Freakonomics, M.D. Thanks again for listening.

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Freakonomics, M.D. is part of the Freakonomics Radio Network, which also includes Freakonomics Radio, No Stupid Questions, and People I (Mostly) Admire. All our shows are produced by Stitcher and Renbud Radio. You can find us on Twitter and Instagram at @drbapupod. This episode was produced by Colleen Pellissier and mixed by Eleanor Osborne. Our senior producer is Julie Kanfer. Our staff also includes Neal Carruth, Gabriel Roth, Greg Rippin, Rebecca Lee Douglas, Morgan Levey, Zack Lapinski, Ryan Kelley, Jasmin Klinger, Jeremy Johnston, Emma Tyrrell, Lyric Bowditch, Jacob Clemente, Alina Kulman, and Stephen Dubner. Original music composed by Luis Guerra. If you like this show or any other show in the Freakonomics Radio Network, please recommend it to your family and friends. That’s the best way to support the podcasts you love. As always, thanks for listening.

BARBER: I have two small children, so all Fri — all days blend into the same together.

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  • Benjamin Barber, professor and researcher at IE Business School.
  • Luis Diesrte, professor and researcher at IE Business School.
  • Joseph Ross, professor of medicine and public health at Yale University.



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