The question is what about a combined residency is interesting to you? What career goal do you have that it will help you get to? If you have a well thought out career plan, the pro is helping you meet that goal. The con is always that it's another 2 years as a resident with all the social sacrifice that entails and you're out $500k in income. The general pros of increased career flexibility and a more well rounded training don't outweigh those cons, you really should either have a specific goal in mind or, less ideally, a passion for both fields and a desire to spend time in both.
Motivations that make sense to me:
- I love EM and hospitalist medicine. I want to practice both and serve as a bridge between the two services and possibly get into higher levels of administration.
- I love EM and CCM, I'm willing to spend an extra year doing the 6 year EM/IM/CCM path to be more well rounded.
- I want to run an emergency department observation unit.
Bad motivations:
- I'm worried about burn-out and have the silly notion that 20 years later I'll work in outpatient medicine after having not done it for decades and it will be more relaxing that just working a shift a week in a sleepy ED.
- I don't know what I want to do with my life so I'm going to commit to 5 years of training with no real goal rather than do 3 years and adjust as needed via job choice, fellowship, or a second residency.