Actually you should mix up all your teaching. Keep it fresh and interesting to your learners. I am getting a Master in Educational Technology and as part of one of my classes I had to design a WebQuest activity. You can learn more about WebQuests from WebQuest.org.
A WebQuest is an inquiry-oriented lesson format in which most or all the information that learners work with comes from the web.
I developed a WebQuest on determining pretest probability. You can look at my WebQuest here. It is geared toward 3rd and 4th year medical students but could be used with residents also. Feel free to use it.
While using the Web to teach is nothing new it is good to change up how you teach. Instead of lecturing on determining pretest probability have your learners do this WebQuest on their own time and flip that part of your lesson on diagnostic testing. It can also be done during class time and many of the WebQuests on WebQuest.org are designed for in-class use. While I had to actually develop/code the website there are online WebQuest creators (just look on the WebQuest.org site for the Creating WebQuests tab).