Time Out” card to make sure everyone is prepared. They regain their individual and collective focus. And only then does everyone step back to the operating table and the surgeon begins repairing the jaw.
I call time-outs like these “vigilance breaks”—brief pauses before high-stakes encounters to review instructions and guard against error. Vigilance breaks have gone a long way in preventing the University of Michigan Medical Center from transmogrifying into the Hospital of Doom during the afternoon trough. Tremper says that in the time since he implemented these breaks, the quality of care has risen, complications have declined, and both doctors and patients are more at ease.
Afternoons are the Bermuda Triangles of our days. Across many domains, the trough represents a danger zone for productivity, ethics, and health. Anesthesia is one example. Researchers at Duke Medical Center reviewed about 90,000 surgeries at the hospital and identified what they called “anesthetic adverse events”—either mistakes anesthesiologists made, harm they caused to patients, or both. The trough was especially treacherous. Adverse events were significantly “more frequent for cases starting during the 3 p.m. and 4 p.m. hours.” The probability of a problem at 9 a.m. was about 1 percent. At 4 p.m., 4.2 percent. In other words, the chance of something going awry while someone is delivering drugs to knock you unconscious was four times greater during the trough than during the peak. On actual harm (not only a slipup but also something that hurts the patient), the probability at 8 a.m. was 0.3 percent—three-tenths of one percent. But at 3 p.m., the probability was 1 percent— one in every one hundred cases, a threefold increase. Afternoon circadian lows, the researchers concluded, impair physician vigilance and “affect human performance of complex tasks such as those required in anesthesia care.”1
Or consider colonoscopies. I’ve reached the age where prudence calls for submitting to this procedure to detect the presence or possibility of colon cancer. But now that I’ve read the research, I would never accept an appointment that wasn’t before noon. For example, one oft-cited study of more than 1,000 colonoscopies found that endoscopists are less likely to detect polyps—small growths on the colon—as the day progresses. Every hour that passed resulted in a nearly 5 percent reduction in polyp detection. Some of the specific morning versus afternoon differences were stark. For instance, at 11 a.m., doctors found an average of more than 1.1 polyps in every exam. By 2 p.m., though, they were detecting barely half that number even though afternoon patients were no different from the morning ones.2
Look at those numbers and tell me when you’d schedule a colonoscopy.3 What’s more, other research has shown that doctors are significantly less likely even to fully complete a colonoscopy when they perform it in the afternoon.4
Basic health care also suffers when its practitioners sail into the day’s Bermuda Triangle. Doctors, for example, are much more likely to prescribe antibiotics, including unnecessary ones, for acute respiratory infections in the afternoons than in the mornings.5 As the cumulative effect of dealing with patient after patient saps doctors’ decision-making resolve, it’s far easier just to write the scrip than suss out whether the patient’s symptoms suggest a bacterial infection, for which antibiotics might be appropriate, or a virus, for which they’d have no effect.
We expect important encounters with experienced professionals like physicians to turn on who is the patient and what is the problem. But many outcomes depend even more forcefully on when is the appointment.
What’s going on is a decline in vigilance. In 2015, Hengchen Dai, Katherine Milkman, David Hoffman, and Bradley Staats led a massive study of handwashing at nearly three dozen U.S. hospitals. Using data from sanitizer dispensers equipped with radio frequency identification (RFID) to communicate with RFID chips on employee badges, researchers could monitor who washed their hands and who didn’t. In all, they studied more than 4,000 caregivers (two-thirds of whom were nurses), who over the course of the research had nearly 14 million “hand hygiene opportunities.” The results were not pretty. On average, these employees washed their hands less than half the time when they had an opportunity and a professional obligation to do so. Worse, the caregivers, most of whom began their shifts in the morning, were even less likely to sanitize their hands in the afternoons. This decline from the relative diligence of the mornings to the relative neglect of the afternoon was as great as 38 percent. That is, for every ten times they washed their hands in the morning, they did so only six times in the afternoon.6
The consequences are grave. “The decrease in hand hygiene compliance that we detected during a typical work shift would contribute to approximately 7,500 unnecessary infections per year at an annual cost of approximately $150 million across the 34 hospitals included in this study,” the authors write. Spread this rate across annual hospital admissions in the United States, and the cost of the trough is massive: 600,000 unnecessary infections, $12.5 billion in added costs, and up to 35,000 unnecessary deaths.7
Afternoons can also be deadly beyond the white walls of a hospital. In the United Kingdom, sleep-related vehicle accidents peak twice during every twenty-four-hour period. One is between 2 a.m. and 6 a.m., the middle of the night. The other is between 2 p.m. and 4 p.m., the middle of the afternoon. Researchers have found the same pattern of traffic accidents in the United States, Israel, Finland, France, and other countries.8
One British survey got even more precise when it found that the typical worker reaches the most unproductive moment of the day at 2:55 p.m.9 When we enter this region of the day, we often lose our bearings. In chapter 1, I briefly discussed the “morning morality effect,” which found that people were more likely to be dishonest in the afternoon because most of us are “better able to resist opportunities to lie, cheat, steal and engage in other unethical behavior in the morning than in the afternoon.”10 This phenomenon depended in part on chronotype, with owls displaying a different pattern from larks or third birds. But in that study, evening types proved more ethical between midnight and 1:30 a.m., not during the afternoon. Regardless of our chronotype, the afternoon can impair our professional and ethical judgment.
The good news is that vigilance breaks can loosen the trough’s grip on our behavior. As the doctors at the University of Michigan demonstrate, inserting regular mandatory vigilance breaks into tasks helps us regain the focus needed to proceed with challenging work that must be done in the afternoon. Imagine if Captain Turner, who hadn’t slept the night before his fateful decisions, had taken a brief vigilance break with other crew members to review how fast the Lusitania needed to travel and how best to calculate the ship’s position in order to avoid U-boats.
This simple intervention is backed by heartening evidence. For instance, the largest health care system in the United States is the Veterans Health Administration, which operates about 170 hospitals across the country. In response to the persistence of medical errors (many of which occurred in afternoons), a team of physicians at the VA implemented a comprehensive training system across the hospitals (on which Michigan modeled its own efforts) that was built around the concept of more intentional and more frequent breaks, and featured such tools as “laminated checklist cards, whiteboards, paper forms, and wall mounted posters.” One year after the training began, the surgical mortality rate (how often people died during or shortly after surgery) dropped 18 percent.11
Still, for most people, work doesn’t involve paralyzing others and cutting them open—or other life-on-the-line responsibilities such as flying a twenty-seven-ton jet or guiding troops into battle. For the rest of us, another type of break offers a simple way to steer around the dangers of the trough. Call them “restorative breaks.” And to understand them, let’s leave the American Midwest and head to Scandinavia and the Middle East.
FROM THE SCHOOLHOUSE TO THE COURTHOUSE: THE POWER
