A debate has erupted within medicine over how to ensure that physicians maintain their clinical skills throughout their careers. The American Board of Internal Medicine (ABIM) has long required internists to pass Maintenance of Certification exams every 10 years to keep their board-certified status. However, this policy has recently come under scrutiny due to its high burden to doctors and the lack of sound evidence that recertification processes improve doctors’ quality of care. In response, the ABIM announced it would offer a new assessment option starting in January 2018, allowing doctors to be recertified through shorter, but more frequent, assessments. But it’s not clear that this will make much difference. In fact, it raises a couple of important questions: Are assessments even the most effective way to incentivize doctors to keep up with the latest medical knowledge and new technologies? Why don’t we directly measure physicians’ quality of care and patient outcomes as they grow older?
While there is some evidence that physicians’ clinical knowledge, adherence with up-to-date standards of care, and performance on process measures may wane as they get older, little is known about whether and how age impacts physicians’ practice and their patient outcomes. On one hand, skills and knowledge are accumulated through experience and can improve quality of care. On the other hand, scientific knowledge, technology, and clinical guidelines change so regularly that keeping up with them and incorporating them into clinical practice can be overwhelming.
As the physician workforce in the U.S. ages (approximately one-fifth of U.S. physicians are over 65 years old, and the size of the group has increased 27% since 2005), it becomes even more important to understand how physician age might relate to patient outcomes. This would help inform new efforts to educate older physicians and improve clinical outcomes.
What the Data Says
The relationship between physician age and patient outcomes has not been empirically studied at a large scale. Therefore, we decided to investigate this issue by analyzing the outcomes of hospitalized Medicare patients and the age of their treating physicians. In our study, which was recently published in The BMJ, we found that U.S. Medicare patients treated by older physicians were more likely to die within 30 days of hospitalization, compared with patients treated by younger physicians — unless the older physicians were used to treating large numbers of patients each year.
We looked at nationally representative data on Medicare patients hospitalized between 2011 and 2014 with a general medical condition and treated by a hospitalist physician, a general internist who specializes in the care of hospitalized patients. Our final sample consisted of approximately 700,000 hospitalizations treated by 19,000 hospitalists in 3,000 hospitals across the United States.
We found that patients treated by older physicians experienced statistically significantly higher mortality rates than patients cared for by younger physicians. Thirty-day patient mortality rates were 10.8% for physicians under 40, 11.1% for those age 40–49, 11.3% for those age 50–59, and 12.1% for physicians age 60 or older. (Because we focused on hospitalists, most of the physicians in our sample were under the age of 50.)
Hospitalists typically work in scheduled shifts, much like emergency room physicians, so patients are unlikely to select the physician who treats them. In effect, the chance nature of patient admissions ensures that patients are randomized to their treating physician, similar to how patients in a clinical trial are randomly assigned to receive a treatment or a placebo. This approach limits the possibility of selection bias that could occur if older physicians tended to treat sicker patients.
We adjusted for patient and physician characteristics that could influence 30-day mortality rates. Patient characteristics included age, sex, race or ethnicity, primary diagnosis, coexisting chronic conditions, median household income, and Medicaid status. Physician characteristics included age, sex, medical school attended, and, importantly, the hospital where they practiced. By accounting for differences between hospitals, we could effectively compare patient outcomes of older and younger physicians within the same hospital.
When we stratified our analysis by the number of patients each physician treated per year, we found that the difference in mortality rates was mostly being driven by older physicians who saw fewer than 200 hospitalized patients annually: They had higher patient mortality rates than younger physicians who saw the same number of patients. We saw no systematic relationship between physician age and 30-day mortality rates among physicians who treated more than 200 patients each year. So, among doctors who saw lots of patients, older doctors seemed to deliver the same quality of care as their younger colleagues.
When we expanded our study population to include general internists, including those who are not hospitalists, our results held: Patients treated by older internists had higher mortality rates than those treated by younger ones.
What These Findings Mean
We were not able to assess exactly why older physicians had worse patient outcomes. One possible explanation could be that it becomes more difficult to keep up with scientific and technological advancement over time.
Another explanation may be that physicians are most skilled in the few years after residency training. Residency is arguably the most intense period of patient care that a physician experiences over their entire career. Young physicians treat many different patients during their residency training, and therefore become familiar with the evidence-based management of a wide array of diseases. It is not uncommon for internal medicine trainees who are finishing residency to be told that they may never know more about the practice of internal medicine than they do at that time. Once they become attending physicians, they generally see fewer patients. And if they later take on management roles or split their time between clinical work and research, they may see even fewer patients. There is reason to believe this could impact their clinical knowledge and patients. Some evidence shows that, in surgical specialties, physicians with lower procedural volumes tend to have worse outcomes.
If this hypothesis about patient volume were true, then continuing medical education and recertification requirements may not be sufficient to prevent the age-related trend in clinical quality. However, we cannot rule out the possibility that doctors who see more patients are somehow systematically different from other physicians. Perhaps, for instance, older doctors who see the highest number of patients do so because they are really good doctors (and love seeing patients).
Another explanation for our findings may be that they reflect differences in how younger and older hospitalist physicians were trained. Since the hospitalist specialty was only recognized in the 1990s, the older hospitalists in our data had transitioned into the hospitalist specialty after beginning their careers as primary care providers, which is an outpatient specialty that focuses heavily on nonacute care, including chronic disease management and prevention.
Unless primary care providers also attend on inpatient services, they likely won’t have lots of ongoing experience with seeing and treating the acute illnesses that hospitalist physicians routinely manage. In contrast, younger hospitalists may have trained as hospitalists right after residency and would therefore be most comfortable and experienced with acute inpatient medicine.
Ultimately, we need to further explore whether physicians’ practice patterns change over the course of their careers and how clinical volumes impact practice patterns and clinical skills among older physicians. There is evidence that continuing medical education is associated with improvements in clinical knowledge, but little is known about whether those activities actually lead physicians to provide higher-quality care. Additional studies will be important for helping physicians consistently deliver high-quality care over the course of their careers and for ensuring that all patients receive the best possible care.
