What do you think the appropriate number of residents/year "off track" should be for a quality program? Everyone gates on so many things on the way in, so should good programs expect this to be a 1% problem or a 10% problem?
I think it depends a bit on the program, the residents, the time period being discussed and a few other factors.
If the program is top notch with stable accreditation that recruits the cream of the crop from the available student pool and then,
suddenly begins to have a much higher number of residents that "wash out" of the program, that should send up some warning flags that something more serious might be going on. However, if a program has struggled and recruits mostly people who were in the fourth quartile of their graduating class and who may have struggled with standardized exams, it might be perfectly normal to expect that some of these low performers might need extra time or may not make it. Basically, a program's finished product (a graduating resident) is often determined by their initial ingredients (the graduating med student). If the students you recruit are low performers, it is hard to turn them into high performers, even in four years. By the time the program meets them, they are full grown adults with established habits and tendencies that difficult to change. So, the bottom line is, programs need to recruit high performing students in order to produce high performing graduates. Obviously, all PD's try to do that. The programs that are not well established or are located in undesirable places may struggle to do that, therefore, they may have more difficulty in getting their residents ready to practice independently.
Similarly, in the late 90's, all programs were struggling because very few med students chose anesthesiology as a career from 1996-1999. Having a pulse was the requirement for getting a very good residency spot. The rich (programs) did okay and the poor struggled to survive. Oral board pass rates dropped into the mid 50% range. I would venture a guess that there was a struggle to get many of those people through residency, as, ideally, the standards do not change just because the quality goes down.
All of that being said, if the number of residents who get held back or dismissed is >~10% or if it is a theme that 1-2 residents get held back
every year, that could be a sign that you do not wish to be there for many different reasons. No one wants to work with a group of residents that struggle, whether it is of their own doing or the program's doing. Keep in mind, that a program that has 20 residents per year, one resident struggling suddenly jumps them into the 5% group. Think back to your med school class or your residency class and realize how many people in those groups were dysfunctional in some area, whether it was academics or professionalism. Five percent seems kind of low when you think about it that way. My own personal experience is that professionalism issues are the toughest issues to deal with and the most likely issue that leads to dismissal. Academic struggles can
usually be overcome with increased studying and diligence. Sociopathic behavior is hard to change.