What is the role of extenders in a surgical practice?

Acta Eruditorum

Abby Van Voorhees

Dr. Van Voorhees is the physician editor of Dermatology World. She interviews the author of a recent study each month.

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In this month’s Acta Eruditorum column, Physician Editor Abby S. Van Voorhees, MD, talks with Alexa Boer Kimball, MD, MPH, about her recent Dermatologic Surgery article, “Practice models and roles of physician extenders in dermatologic surgery.”

Dr. Van Voorhees: What made you choose to study physician extenders in dermatologic surgical practices?

Dr. Kimball: There has been a substantial increase in the employment of physician assistants and nurse practitioners in dermatology practices over the last five years. One of the pieces of conventional wisdom out there was that perhaps these providers were doing primarily medical dermatology in order to support the procedural aspects of the practices. Some of our previous work compared the practice profiles of extenders in medical versus surgical practices. But, we thought it was important to see what the differences might be between different types of surgical practices. We also recognized that the types of training that different extenders get varies and wanted to make sure we had figured out what their scope of practice was in a procedurally oriented setting.

Dr. Van Voorhees: Who are the groups being studied?

Dr. Kimball: Within the primarily surgical dermatology practices, we looked at two different groups of dermatologists. One was a group that had completed a Mohs fellowship, and one was a group that was practicing Mohs but had not been fellowship-trained.

Dr. Van Voorhees: How much surgery does one have to be performing in order to qualify to be a non-Mohs trained practitioner?

Dr. Kimball: For the purposes of this analysis, we studied respondents to the AAD Practice Profile Survey who said they were performing Mohs but were not fellowship trained. Typically, these practitioners were performing around 20 Mohs cases per week.[pagebreak]

Dr. Van Voorhees: Did you see a different spectrum of procedures that each of these groups performed or were they similar regardless of their prior training?

Dr. Kimball: There are differences. The fellowship-trained surgeons performed more Mohs and reconstructions, whereas the non-fellowship-trained surgeons tend to do more excisions and benign and premalignant destructions, and had a higher case volume. So we think that there are some differences in patterns.

There are a number of economic reasons you can envision where fellowship training might then affect the type of practice you’d have — and if you trained in a Mohs fellowship you might really want to do that all the time, whereas that might be different if you didn’t train in a fellowship and Mohs is part of your armamentarium but not your focus.

Dr. Van Voorhees: How about the practice settings? Were there differences between these groups in terms of the percentage that were in an academic vs. private practice?

Dr. Kimball: The academic centers have a predilection for fellowship-trained people — fellowship-trained Mohs surgeons were twice as likely to practice full-time in an academic setting, so they therefore are likely to have a large number of medical dermatologists who are sending referrals to them. So they also probably have more opportunity to have a very Mohs-focused practice. And we see that people who are fellowship-trained are more likely to be doing more Mohs and fewer routine excisions. The non-fellowship-trained tend to do other things as well. They also tend to do more botulinum toxin, fillers, and lasers. Mohs is part of their practice but it’s not the focus of their practice.

Dr. Van Voorhees: What did you find in your study? Were physician extenders used differently in these two types of physician practices? Were there similarities noted?

Dr. Kimball: What I think was important to note was that about 75 to 80 percent of the time of the extenders in both of these types of practices was spent doing medical dermatology. That’s not a whole lot different than you’d expect in a general dermatology practice. When I mentioned previously that the conventional wisdom was that in surgical and cosmetic practices the extenders were doing only medical dermatology to support the practices, in fact what the extenders were doing was very similar to what you’d see in a general dermatology practice.

We did see in the fellowship-trained practices that the extenders tended to do slightly less cosmetic dermatology; in the non-fellowship-trained practices they tended to do more cosmetics. That’s consistent with the profiles of the non-fellowship-trained surgeons, who themselves tended to do more botulinum toxin, more fillers, and more routine excisions and less Mohs.

In other words, the extenders in these practices mostly resemble extenders in practice in general. There’s a slight twist in how they spend their procedural time that reflects their supervising physician.[pagebreak]

Dr. Van Voorhees: Was there a difference in the types of extenders utilized by these different types of practices?

Dr. Kimball: The growth has been primarily in PAs, but there certainly are a number of NPs as well. There were more PAs in the non-fellowship practices while the proportion of practices employing NPs was essentially the same across the two types of practices.

Dr. Van Voorhees: Was there a difference in the number of patients seen each day by the physician extenders?

Dr. Kimball: The non-fellowship-trained Mohs providers see substantially more patients, consistent with the larger number of smaller procedures they perform. But extenders in both settings saw equivalent volumes.

Dr. Van Voorhees: Was there a difference in amount of supervision?

Dr. Kimball: Fellowship-trained surgeons were more than twice as likely to directly supervise their extenders; i.e., all patients were directly presented to them.

Dr. Van Voorhees: What should we take away from this study?

Dr. Kimball: First, I think we need to continue to keep an eye on how NPs and PAs are supervised and trained. A surgeon supervising someone doing primarily medical dermatology, for example, has to maintain a high level of proficiency in medical dermatology. But, the main takeaway from looking at how procedures fit into dermatology practice is that most dermatologists perform a lot of procedures in their practices; between surgical and cosmetics it’s about 35 percent of physicians’ time. It is really a critical part of our training and a critical part of our identity. As we move forward into an era where increasing scrutiny on credentialing and training and documentation of experience becomes increasingly important, those in the procedural areas will definitely have to continue to respond to increasing demands for documenting proficiency. There are differences based on some of those types of experience and credentialing, such as fellowship training, that we can see already.

Dr. Kimball is vice chair of the department of dermatology at Massachusetts General Hospital and director of the Clinical Unit for Research Trials and Outcomes in Skin (CURTIS). She is also an associate professor of dermatology at Harvard Medical School. Her article was published in Dermatologic Surgery, 37(5):677-83 (May 2011) after being published online April 14, 2011. doi: 10.1111/j.1524-4725.2011.01984.x.