An integrative literature review (sometimes called an IR or a Systematic Integrative Review) is:
A method that summarizes past empirical or theoretical literature to provide a more comprehensive understanding of a particular phenomenon or healthcare problem.
In the same way as a systematic literature review does, the write up of the integrative review literature search needs to explicitly state the search terms and databases used, as well as the criteria used for including and excluding sources. The University of Waikato’s Library Search is great for getting a sense of the literature, but it is a search engine, not an individual database. When conducting the definitive searches, you need to go to individual databases.