Who are peers?
A jury of your peers? The bad influences our parents warned us about?
Peer -
A person who has equal standing with another or others, as in rank, class, or age.
From The American Heritage Dictionary of the English Language (2011)
Peer–review -
A process by which something proposed (as for research or publication) is evaluated by a group of experts in the appropriate field.
From Merriam-Webster's Collegiate Dictionary (2012)
Most medical, scientific, scholarly, or academic journals have their articles peer-reviewed before they are published. Other doctors, researchers or scientists who know a lot about the topic review the article, the research methods, and the statistical formulas used to see if the study seems valid and worthwhile. It is a form of quality control.
Any ProQuest database that contains Peer-reviewed articles has a check-box under the search area called Peer reviewed. Check it before you do your search, and the results will come from peer-reviewed journals:
CINAHL contains many Nursing & Allied Health journals, and major medical journals. Scroll down until you see Peer Reviewed on the right, and check that box: