Skip to Main Content

When it comes to the medical care you receive, it shouldn’t really matter whether you see your doctor in the morning, the middle of the day, or late in the afternoon. But it can.

To investigate the effect of time of day on decisions about cancer screening, my team at the Penn Medicine Nudge Unit and I recently examined primary care doctors’ orders for screening tests across the course of the day. We focused on visits with patients who were eligible for either breast or colon cancer screening. We also followed the patients for one year to see who completed these tests and whether or not the visit time mattered there, too.

As we report Friday in JAMA Network Open, in almost every doctor’s practice we found the same pattern. Patients seen earlier in the day were more likely to have their doctors order cancer screening tests. At 8 a.m., for example, 64% of women eligible for breast cancer screening left their appointments with an order for a mammogram. That declined to 48% by 5 p.m. We saw a similar pattern for colon cancer screening: At 8 a.m., 37% of those eligible left with colonoscopy orders compared to 23% by 5 p.m.


The same trend held true for patients. One year later, those who saw their doctors later in the day were much less likely to have completed their screening tests.

These gaps in preventive care are not only limited to cancer screening. In another study of ours, we found similar trends in flu vaccination. On top of that, primary care appointments later in the day have higher rates of unnecessary antibiotic prescribing and higher rates of prescribing opioids for back pain. There’s even evidence from within hospitals that providers wash their hands less often toward the end of clinical shifts.


Two main factors may be at play in terms of how doctors and patients make decisions, particularly toward the end of the day.

The first is a phenomenon known as decision fatigue. It’s the tendency to make poorer choices following a long stretch of making a lot of other decisions. Grocery stores take advantage of this by placing candy near the checkout line. After making many decisions about which foods to purchase, consumers may make less healthy choices toward the end of their shopping.

Decision fatigue likely affects doctors and patients in similar ways. As doctors make repeated decisions throughout the day, this fatigue may lead them to stop engaging patients in discussions about the same decisions later on. Patients also make decisions throughout the day, whether at home, at work, or elsewhere. When asked about their interest in cancer screening at the end of the day, patients may be more likely to defer the decision to the future.

Another factor stems from what’s happening with doctors’ schedules. Say a doctor has 15 minutes allocated for each patient throughout the day. At 8 a.m., she has the full 15 minutes. But if she falls behind schedule, she may be left with four patients to see in the last 30 minutes. This can lead to rushed visits during which conversations about health care decisions may not be brought up or are deferred. Patients may also be rushed at the end of the day simply because they want to get home.

Although these factors may seem impossible to address, our group has found that simple changes to a doctor’s practice and the design of electronic health records can go a long way.

Repetitive decisions, like asking every patient during flu season if he or she has gotten the influenza vaccine, offer an example. Rather than leaving it up to doctors to remember to mention vaccination, the electronic health record can nudge medical assistants to start this discussion with patients before they see the doctor, accept or cancel a vaccine order based on the response, and queue it up in the health record for the doctor to review. We tested this approach and found it increased flu vaccination rates by 10%. In clinics that used this nudge, patients who saw their doctors at the end of the day had similar vaccination rates as patients with 8 a.m. appointments in clinics that didn’t implement this approach.

Some decisions don’t need to be made during a doctor’s visit. We’ve found improvements in colon cancer screening rates by offering to mail colon cancer tests to patients’ homes. We’ve also found that sending doctors lists of their patients who, based on national guidelines, could benefit from cholesterol-lowering medications tripled the rate of statin prescribing.

The take-home lesson from this work is that medical decisions made later in the day may not be as good as those made earlier, but that subtle changes to electronic health records and taking new approaches to delivering care can make time irrelevant.

Simple decisions can have long-lasting effects on health, so know what’s important to you and make sure your doctor knows it, too, regardless of the time of day.

Mitesh S. Patel, M.D., is director of the Penn Medicine Nudge Unit, an assistant professor at the University of Pennsylvania, and a staff physician at the Cpl. Michael J. Crescenz Veterans Affairs Medical Center in Philadelphia.

  • The scale of this research is not stated in the article but assuming that criteria were met for reporting in JAMA the findings of the seemingly simple research are highly disturbing. Health care at the Doctor’s office is better in the mornings ………… There are however immediate and also simple solutions for more consistent patient care: Doctors need to allot more time per-patient time, take a good lunch-break, earn a little less by adding more colleagues in their practices. A rather simple problem (with dire consequences) has an equally simple solution – the same as applied in ANY other business / work environment. Thanks for the very valuable research, hope it get the attention it deserves !!

  • Bonus question:
    Are patients known to be randomly distributed during the day? Maybe early bird patients tend to be older and therefore are enriched for needing cancer testing.

Comments are closed.