They do change (adding Metronidazole to ok in pregnancy from 2001 to sometime in 2005-2009).
But the significant amount of change is negligible. Here's the thing. Step 2 is all about giving you the necessary information to make a diagnosis and to know how to work it up. Its all about classic presentations and the typical workup, and every once and a while, treatment.
But Step 1 and Step 2 never get lost in the detail. If it does, its based mostly on theory, not on practice. For example, you are rarely asked the difference between Lantus or Levemir (they are both long acting insulins).
To take it further, if you think some one has pneumonia, the most common bug in 1870 was Strep Pneumo. The most common bug in 1925 was Step Pneumo. The most common bug in 1996, 2001, 2005, and 2011 is Strep Pneumo. So that isn't going to change. You have a patient with a fever and a cough, tachycardia, and purulent sputum. Yeah, thats pneumonia. What are you going to do? XRay. That hasnt changed in 50 years.
Bottom line, you might miss one or two questions of 400 getting an older version and missing one small piece. But the chances that you would remember the outdated detail AND not be corrected by a Qbank AND would have otherwise gotten the right answer is so negligible that the one wrong answer you get because you got the notes is totally worth the 75 answers you got right because of the notes.
