If you need surgery, it should reassure you to know that researchers have been studying factors that predict surgical success or failure for years. Some of the most important findings have been ones you might expect.
For example, studies have found that hospitals and medical centers that perform a lot of hip and knee replacements tend to have lower complication rates than those performing fewer operations. As a result, there is a trend for people needing these surgeries to have them performed at high-volume centers. Similarly, surgeons who frequently perform hip or knee replacement surgery tend to have better results than those who perform them rarely. Studies like these have been published for a number of other operations and conditions.
Less obvious factors to consider in scheduling surgeries
It might surprise you to learn that less obvious factors have also been studied. For example, researchers have examined whether
- surgical outcomes are worse at teaching hospitals in July, when new medical and surgical trainees begin (a phenomenon called “the July effect”). The findings are mixed: some studies find it’s true and others debunk the idea.
- music played in the operating room — including loud or soft, classical or upbeat, or no music at all — is helpful or harmful. Again, the evidence is mixed.
- surgical success may vary based on the dominant hand of your surgeon. In one study of cataract surgery, patients operated on by left-handed surgical trainees had fewer complications than those operated on by right-handed trainees.
Another surprising surgical study: Birthdays
A new study published in the medical journal The BMJ attempted to answer a question I would never have thought to ask: if a surgeon performs an operation on his or her birthday, does it affect the chances that their patient will survive?
Putting aside for a moment why these researchers thought this was a worthy research question, let’s look at how the study was performed and what the researchers found. They analyzed survival data from nearly a million emergency operations performed by more than 47,000 surgeons in the US between 2011 and 2014. All patients were at least 65 years old and had one of 17 common emergency operations, such as coronary artery bypass surgery or gallbladder removal. While emergency surgeries aren’t planned, depending on the situation they may not need to be performed on the day of diagnosis.
The study found that more patients died within a month of surgery when the operation was performed on the surgeon’s birthday (6.9%) than on other days of the year (5.6%). The difference was statistically significant, and did not seem to be due to any alternative explanation the researchers could identify, such as whether
- surgery dates were moved a bit sooner or later based on the surgeon’s birthday
- a small number of surgeons might have had high complication rates that could skew the results
- there were variations in surgical complexity, frequency, or type
- surgeons might have deliberately avoided performing surgery on their birthday
- the birthdays were “big ones” (such as turning 60) or fell on a weekend.
Statistical methods were applied to reduce or eliminate the possible impact of each of these potential explanations. Interestingly, no effect of the surgeon’s birthday was found for planned (non-emergency) surgeries.
Why would surgical success depend on whether it’s the surgeon’s birthday?
It’s fair to ask whether there is a plausible explanation for how a surgeon’s birthday might affect surgical success.
The authors of the study suggest that the findings demonstrate how “surgeons might be distracted by life events.” But what does this mean? Were the surgeons less focused? Were they rushing the surgery to get home sooner to start celebrating? Did the excitement of their birthday somehow affect physical performance of the surgery? All of these potential explanations (and, perhaps, others you could suggest) are speculative, since the study did not focus on why the results were observed.
The bottom line
It’s tempting to dismiss the results of this study as “don’t believe everything you read.” After all, it’s only one study, and there is no compelling or obvious way to explain the findings. And it doesn’t seem practical for a person in need of emergency surgery to try to find out when their surgeon’s birthday is and, if it’s the day of the surgery, ask for another surgeon.
Then again, the case could be made that until we know more, perhaps emergency surgeons’ on-call schedules should be adjusted to avoid assignments on a surgeon’s birthday. The patients might have modestly better outcomes, and the surgeon might have something truly special on their birthday: a day off from surgery.
Follow me on Twitter @RobShmerling