The book is pretty much ONLY practice questions, with rationales. So far I've primarily used the accompanying CD, and I have several issues with their questions. The authors claim their question database is 1,000+, however, I've only taken two practice tests and already have had way too many repeat questions which threw off my second score. I have noticed SEVERAL editing mistakes, some of which did change the meaning of the sentence, making part of their rationale inaccurate. A few of the correct answers did not match the rationale, making you wonder which way they intended the meaning to be (so then of course you look it up to double check). One example of this is the "correct" answer was "annual pneumococcal and influenza immunizations" but the rationale states that pneumococcal vaccines are NOT given annually (which is true). Sure, that's not too big of a mistake, but it's terribly annoying and decreases your faith in the author's ability to be preparing you for such an important exam. There were several other answers that I'm really not sure were the best answer or even completely correct. This book probably is still helpful, at least for getting used to answering the question and the testing style. Overall, the information most likely is helpful as well, but it also seems limited-many topics were repeated too often, whereas other topics seem to be left out completely. I'm not sure I should even give it 3 stars. . .we'll see after I take the test.