"The peer review process exists to afford some level of quality assurance before material being published." "Peer review distributes the author’s work to a panel of health care professionals with expertise in the topic area and requests their appraisal of its merits, weaknesses, and suitability for publication."
Alspach, J. G. (2016). Preparing a Paper for Publication: Help Us Help You Make It Happen. Critical Care Nurse, 36(3), 7-10. doi:10.4037/ccn2016777
There are two ways to determine if an article is peer-reviewed.
1) use the peer-review filter in CINAHL (see the powerpoint for instructions)
2) Locate a particular journal's web site and look in "Instructions for Authors". See the example in the blue tab above labeled "Determining if a Journal is Peer-Reviewed."
NOTE: PubMed does NOT have a have peer-review filter.