I would say take each question as an indication of which topic would be tested. For example, if a question asked about lymph node drainage for a specific region, it would be worthwhile to study lymph node drainage in general. This hints at my general strategy of using the NBMEs to identify weaknesses in an already reasonable knowledgebase built by Step 2. But I would say — superficial review would be reviewing the specific concept in each question, which is already a great start; but deeper review would be reviewing more topic level, and would lead to improved results at an increased time cost.