Surgeon age and complications

As much as I try to deny it, I can't anymore. Now that I'm on the wrong side of 40, I have to face what we all eventually have to face, the fact that we will age and that our physical and some of our mental abilities will decline. For some of us, the decline will be slow, and we will retain much of our previous abilities into our 60's, 70's, and even 80's. For others, the decline may not be so slow. We all have experience seeing people in their 50's or 60's who look and move as though they are in the 80's, and we all hope that we will be in the former group, retaining most of our physical and mental faculties, plus a leavening of experience that keeps our abilities sharp.

For surgeons, this is a particularly important issue, because far more than any other specialty surgery requires manual dexterity and good vision, in addition to the sharp mental faculties that all physicians should possess. The other day, I was perusing the huge pile of journals that had accumulated during my vacation. I happened to pick up the Septemeber issue of Annals of Surgery and was idly flipping through it when I came across a rather fascinating attempt to measure the effect of age on surgeons' abilities, straight from my old alma mater, the University of Michigan:

Waljee JF, Greenfield LJ, Dimick JB, Birkmeyer JD (2006). Surgeon age and operative mortality in the United States. Ann Surg 244(3):353-62.

Here's the abstract:

Objectives: Although recent studies suggest that physician age is inversely related to clinical performance in primary care, relationships between surgeon age and patient outcomes have not been examined systematically.

Methods: Using national Medicare files, we examined operative mortality in approximately 461,000 patients undergoing 1 of 8 procedures between 1998 and 1999. We used multiple logistic regression to assess relationships between surgeon age (<=40 years, 41-50 years, 51-60 years, and >60 years) and operative mortality (in-hospital or within 30 days), adjusting for patient characteristics, surgeon procedure volume, and hospital attributes.

Results: Although older surgeons had slightly lower procedure volumes than younger surgeons for some procedures, there were few clinically important differences in patient characteristics by surgeon age. Compared with surgeons aged 41 to 50 years, surgeons over 60 years had higher mortality rates with pancreatectomy (adjusted odds ratio [OR], 1.67; 95% confidence interval [CI], 1.12-2.49), coronary artery bypass grafting (OR, 1.17; 95% CI, 1.05-1.29), and carotid endarterectomy (OR, 1.21; 95% CI, 1.04-1.40). The effect of surgeon age was largely restricted to those surgeons with low procedure volumes and was unrelated to mortality for esophagectomy, cystectomy, lung resection, aortic valve replacement, or aortic aneurysm repair. Less experienced surgeons (<=40 years of age) had comparable mortality rates to surgeons aged 41 to 50 years for all procedures.

Conclusions: For some complex procedures, surgeons older than 60 years, particularly those with low procedure volumes, have higher operative mortality rates than their younger counterparts. For most procedures, however, surgeon age is not an important predictor of operative risk.

The reason for this study, aside from normal common sense knowledge that we all suffer declines in some of our abilities as we age, comes from several studies in the primary care literature that suggest an inverse relationship between age and physician performance. According to several studies, older physicians are less likely to be up on the most current studies, tend to be more likely to use older treatments that have been supplanted by superior treatments, and to perform more poorly on recertification examinations for their Boards. For surgeons, the data is mixed, as the authors point out:

Whether physician age is related to clinical performance in surgery is not well established. Compared with primary care, the practice of surgery may present different challenges for the older physician. Complex procedures are long and require considerable physical and mental stamina. Previous research demonstrates that manual dexterity, strength, and visuospatial ability decrease with age, along with cognitive skills and abilities to sustain attention. Nonetheless, it has not been established whether such factors imply worse outcomes for patients. Two studies have suggested increased mortality rates for older surgeons with coronary artery bypass grafting and carotid endarterectomy, while others have pointed to surgeon youth and inexperience as more important risk factors.

They ain't kiddin'. When I was in my twenties and going through residency, I marveled at how some of thse surgeons, twice my age or even older, could go through 10 or 12 hour surgical tour de forces they way they did, resting only for perhaps a single bathroom break. One surgeon in particular, who was in his late 50's or early 60's was known for on occasion lining up elective vascular access procedures and operating well into the night and beyond, to the mixed joy and chagrine of the on call junior residents. (Joy because we got to operate; chagrin because it would mean little or no sleep the nights he decided to do this.) Of course, vascular access procedures (shunts for dialysis primarily) could be done sitting down. This surgeon, however, could pull all-nighters with the best of them doing kidney transplants. Of course, most nights he got to go home and get a good night's sleep, and we residents were on call every third night and working 14 hour days the rest of the time. (Yes, those were the "good" old days, before work hour restrictions. Note the quotation marks.)

The investigators decided to look at the in hospital mortality rates for eight procedures using Medicare eligibility files and Medicare records from 1998-1999: coronary artery bypass grafting (CABG), carotid endarterectomy (CEA), aortic valve replacement (AVR), elective repair of abdominal aortic aneurysm (AAA), lung resections for cancer, esophagectomy, cystectomy (bladder removal), and pancreatectomy (including the Whipple procedure). In hospital mortality (defined as death before discharge or within 30 days of surgery) is a commonly used endpoint because it is correlated with technical skill and because it is an unequivocal measure. (Either the patient died or he didn't.) They then looked at surgeon age (40 or younger, 41-50 years old, 51-60 years old, or 61 years old and older), as well as surgical volume (the number of each procedure per year) that the surgeons in the study carried. Results were controlled for patient factors, such as age, acuity, elective versus emergency, gender, and preexisting conditions like diabetes or heart disease.

Surprisingly, the effect of surgeon age was not significant for most procedures. Differences were seen only for CEA, CABG, and pancreatectomy. The money chart is this one (click to enlarge):

As this clearly shows, even for these procedures the effect is smaller or even nonexistent in high volume surgeons and most pronounced in surgeons who do a low volume of the procedure in question. Another telling feature of this graph is that surgeon volume appears to be a much stronger indicator of mortality rates than age. This effect is most pronounced for pancreatectomy, where among younger surgeons, there is a three-fold increase in mortality rates going from high volume to low volume surgeons, whereas among low volume surgeons, by comparison the mortality rate increases only 56% The lesson? For these three highly complex procedures, surgeon volume probably correlates with outcome far more than surgeon age, and the worst outcomes tend to be from older, low volume surgeons. Indeed, among surgeons 61 and over, the increase in mortality for pancreatectomy going from the highest to the lowest volume surgeons was nearly 6.2-fold, and the oldest high volume surgeons appeared to do better than the youngest high volume surgeons, but it was not statistically significant.

Obviously, measuring in hospital death is a very blunt instrument. This study says nothing about whether surgeon age correlates with lesser complications, although, as the authors point out, there are studies that suggest, for example, that hernia recurrence rates than younger surgeons, but this is for laparoscopic hernia repair, not the traditional open repair. Given that laparoscopic inguinal hernia repair has only become prevalent over the last decade or so, young surgeons have the advantage of having learned this procedure during their residencies, while older surgeons have had to pick it up by other means, underlining once again the problem of how to train established surgeons to do new procedures safely. It also says nothing about less complex and morbid surgeries. Further studies will have to address that. What it does tell us is that the way older surgeons often try to ease their way into retirement may not be the best approach for our patients:

Our findings also have implications for practicing surgeons. Many surgeons approach retirement by gradually tapering off their clinical practices and operative volumes. Our findings suggest that, for some procedures, this strategy may not be optimal from the perspective of patient safety.

For complex procedures, this is likely true. One strategy that some older surgeons that I've known have taken is to stop doing the really big cases, farming them off to their younger colleagues or assisting their younger partners, while continuing the less stressful and demanding operations. In light of this data, this seems like a reasonable way to proceed. Even so this study is very reassuring in that the age-related differences in outcome among surgeons are relatively small, even in the procedures where a difference was detected. As the authors conclude:

From the perspective of patients facing complex surgery, this study suggests that surgeon age should not be a primary factor in choosing a surgeon. Surgeon age is a relatively weak predictor of operative mortality in aggregate and certainly much worse for discriminating performance among individual surgeons. Instead, other surgeon characteristics may be more important, including risk-adjusted outcome measures when available and reliable, hospital and surgeon volume for selected procedures, and, perhaps, other less quantitative factors, such as surgeons' local reputations.

Or, as Dr. John Birkmeyer put it:

Practice keeps skills high, so an all-or-nothing approach to surgery in the pre-retirement years may be better than gradually fading away, said study co-author Dr. John Birkmeyer of the University of Michigan.

"Those who continue to practice in high-risk areas should maintain their caseloads, but it may be a good idea when surgeons get into the pre-retirement mode that they give up the most complicated and high-risk surgeries altogether," said Birkmeyer, who is 43.

Patients should ask how many procedures a surgeon does a year, rather than focus on the doctor's gray hair, Birkmeyer said.

Common wisdom among surgeons is that a surgeon is at the height of his or her abilities between 5-15 years out from residency, give or take, where a surgeon has had enough time to acquire "seasoning," but is still young and current with the latest techniques. That is the cliche, anyway. This study suggests that, for complex procedures, there is little difference among age groups, except for the oldest surgeons. (The study does not address the question of whether the youngest and most inexperienced surgeons also have similarly elevated mortality rates.)

I find that reassuring, both as a surgeon and as a potential patient.