Evidence Based Decision-Making is a process for making decisions about a program, practice, or policy that is grounded in the best available research evidence and informed by experiential evidence from the field and relevant contextual evidence.
Your keywords are the most important and descriptive words in your research question. Try to avoid initially looking for resources that support only one opinion.
Question: Is a butterfly needle or a straight needle preferable for patients with fagile veins?
Keywords: Butterfly needle - straight needle - fragile veins
You may need to look for articles that only cover one area of your question.
Search 1. "Butterfly needle" AND "fragile veins"
Search 2. "Straight needle" AND "fragile veins"