When I was a medical student, I thought I wanted to be a radiologist. I love the science. I like the physics of radiation, and my ego was invested in the idea of being a “doctor’s doctor” that other doctors looked to for wisdom and interpretation of diagnostic testing. Radiology checked all those boxes without the ooey-gooey autopsies and whatnot that are part of the daily routine of pathologists.

Then I did a radiology rotation.

I truly did like the science of x-rays and the conversations with other doctors and all the rest. I discovered one problem, though: I could not stay alert for hours at a time in a dark room looking at films. Come two or three o’clock in the afternoon, I would inevitably start to fade. Once, I even nodded off in the radiology suite. So, with the safety of future patients in mind, I decided to go a decidedly more well-lit and upright route, eventually completing a residency in internal medicine and a fellowship in endocrinology, diabetes, and metabolism. If nothing else, the work in endocrinology was ambulatory. If I’m moving, I can’t fall asleep.

I review my personal history as a wind-up for a research paper in JAMA Health Policy this last week (paywall). Investigators looked at records from primary care practices–these studies always pick on primary care docs–to see how likely a patient was to receive a “statin” medication depending on the time of day of his or her appointment. This is no casual question. Viral pandemics aside, cardiovascular disease remains the leading cause of death in the United States. Appropriate use of statin medications like atorvastatin (Lipitor), rosuvastatin (Crestor), and others dramatically reduce the risk of death from any cause in people at risk for heart disease.

Using United States Preventive Services Task Force (USPSTF) guidelines, which state that we should offer statins to anyone with known vascular disease, anyone with a diagnosis of a genetic problem called “familial hypercholesterolemia,” or anyone with a low-density lipoprotein (LDL) cholesterol level of 190 mg/dL or more (among other diseases like diabetes), the researchers found a disturbing trend. Compared with 8 am appointments, which the investigators used as their reference group, the likelihood of getting a statin was lower at all hours except 9 am. And the likelihood of getting a statin pretty consistently fell as the day went on: 88% at 9 am, 63% at 12 pm, and 69% at 3 pm. Overall, you were only 69% as likely to get an appropriate statin prescription in an afternoon appointment as you were in a morning appointment. Here’s the raw, “unadjusted” data:

And yes, radiologists make more mistakes later in their shifts, too. But this phenomenon is not limited to doctors. Judges sentence defendants more harshly just before lunch, when they’re hungry, and sentence more leniently after a break. Car crashes peak between 5 and 7 pm. Students taking standardized tests perform better earlier in the day and recover performance after rest. If you’re like me, you may have found that you do your best creative work earlier in the day, and you’re better off going to meetings or working on a task list later in the day.

The wellness industry has long coached patients to get the earliest available appointment of the day, but our reasoning has had more to do with the fact that if you go earlier in the day, you’re less likely to have to wait. With this data, we have to consider not only the time in the waiting room but the outcome of the visit.

[Disclaimer: the Kansas Business Group on Health has CDC funding to encourage appropriate use of statin medications.]

As the Medical Director of the Kansas Business Group on Health, I’m sometimes asked to weigh in on hot topics that might affect employers or employees. This is a reprint of a blog post from KBGH.