The search boxes have dropdown menus with many options that allow you to limit to all text, abstracts, authors, and countries, dates, MeSH terms, down to title, volume and DOI. You may also limit to publication type, such as systematic review, as in this example:

If you scroll down below the search boxes when you open MEDLINE in EBSCOhost (also called EBSCO), you'll see that there are many ways to limit a search:

• By type of study to type of subject, age groups studied, and more. 
• To search within the full text of articles, to find related words, to apply equivalent subjects, and to limit to full text. 
• To limit to Evidence-based Medicine (EBM) AND/OR to systematic reviews. 
• To limit to human subjects or use a menu of possible animals to choose the study subjects.