Also at your disposal full-text-search by resources. It presents with _text - search by narrative and _content - search by remaining resource content.
Search results can be sort by rank with _score search-parameter value. More relevant results will be on top but reversed order also supported through
Full-text search requests supports grouping and logical operations
GET /Patient?_content=(NOT bar OR baz) AND foo
If you wanna search by the phrase - just quote it
GET /Patient?_content="Mad Max"