LET'S REVIEW:
TWO BEST APPROACHES FOR FINDING EVIDENCE

  1. Randomized Controlled Trials are the FIRST tier approach for finding evidence in the biomedical journal literature.

  2. The SECOND tier approach is to identify articles that have been reviewed by premiere resources in evidence-based practice: articles contained in the Evidence Based Medicine Reviews (EBMR) databases.

These are both LIMIT options, that you apply to your search after you have identified and searched for each important concept in your topic, and combined these concepts together using the boolean AND.