You will need to carefully record your search strategy to ensure it is reproducible and verifiable, especially for publication.
How? For each search, record the name of the database, the years covered, the date you searched and your exact search strategy, including all the terms you have used. One way to record your searches is to save the search history from each database. To do this you will need to create an account with the database provider - select My Account (in Ovid databases), Sign In (EbscoHost or Proquest) or Register (Web of Science).
Here's an example: Date: 11 September, 2018. Database: Ovid MEDLINE 1946 to August Week 5 2018
|1.||(aged or elderly or frail).ti,ab|
|2.||exp Health Services for the Aged/ or exp Homes for the Aged/ or exp Nursing Homes/ or exp Geriatric Nursing/ or exp Aged|
|3.||1 OR 2|
|6.||4 OR 5|
|7.||(uti or "urinary tract infection*").ti,ab|
|8.||Urinary Tract Infections/|
|9.||7 OR 8|
|10.||3 AND 6 AND 9|
|ti,ab = Title or Abstract … / = MeSH term; exp … / = exploded MeSH term|
Now translate your search into other databases you are using, taking into account the unique language of each database - what symbols are used for truncation, wildcards, and so on, and the thesauri terms if applicable.
You will most likely have to go back and refine your searches as new terms and subject headings present themselves. This will be an iterative process and can be helped by keeping a search planner as a living document throughout the process. Deakin University has a suggested search planner here which you could adapt.
For some great examples of how to record your search framework and strategy across various disciplines and databases, see Chapter 7 of this eBook: Foster, M. J., & Jewell, S. T. (Eds.). (2017). Assembling the pieces of a systematic review: A guide for librarians. Lanham, Maryland: Rowman & Littlefield.