CINAHL is the only database that has a limiter/filter for Any Author is a Nurse
In some databases, it is possible use the Author Field to search for initials (BSN, RN, MSN, CNP, DNP, etc). This is not 100% accurate.
In some databases, like MAG Online Library, initials often aren't listed after the author name. You will need to check the author's credentials either by clicking on their name or looking at the PDF of the article.
In any Nursing, Medicine, Science, or Multidisciplinary resources it is always your responsibility to check the author's credentials, affiliated institution, and area of expertise.