Narrowing to Articles Likely to be Written by Nurses
There are ways to narrow your CINAHL and PubMed retrievals so it is more likely that at least one author is a nurse, but these methods are not perfect. They can potentially eliminate some results that are written by nurses.
The authors' credentials are usually not visible in the article record of PubMed or CINAHL, so you still have to look at the actual article full text article to confirm the authors' credentials.
Occasionally, author credentials are not indicated in the actual article, or they may be unfamiliar credentials if the author is not based in the United States. You may need to use the internet to attempt to confirm the authors' credentials.