Systematic reviews: Medline

• bibliographic database indexing about 5,600 medical and health care journals
• wide topic coverage including biomedicine, allied health, nursing, biological and physical sciences, mental health, medicine and health care
• records start in the early 1800's and are updated daily (dates of coverage change constantly)
• US focus but includes a large international collection (Embase has a more European focus)
• Ovid Medline ALL = Pubmed. You do not need to search both.

1. Download and print our helpsheet on searching Medline.
2. Watch the video - it will take you step by step through the same search.
3. Work through the helpsheet using the sample topic. This will confirm the basic search process.
4. When you are confident with using subject headings, textwords and combining concepts with AND/OR, use the same technique with your own topic.
5. It may take several attempts to refine your search strategy. That is normal.

Don't confuse the name of the database with the years of coverage

Database content constantly changes and records are added retrospectively so years of coverage are fluid.

It is important to understand that the years indicated in a database name – such as Ovid MEDLINE(R) ALL <1946 to present> often refer to the date the catalogue started (1946 in this case) and not to the date of the earliest publications indexed in the database, which in Medline go back to the late 1700s.

For many bibliographic databases it is not possible to accurately define the years of coverage. That is why we keep these records for systematic reviews:

• the full name of the database on the day you searched it eg Ovid MEDLINE(R) ALL 1946 to August 11, 2020 (copy and paste this from the database when you are searching it - in Ovid it sits above the search box)
• the full search strategy, including any limits
• the date you carried out the search
• the number of results you retrieved on that day

Don't 'limit to humans'

If you select 'limit to humans' you risk losing all non-indexed and pre-print publications in a database which have not been indexed as 'human'. This could be thousands of records.

Instead, remove the animal studies

A safer alternative is to search for the things we don't want (in this case animal studies) and remove them from the results. Adjust the line numbers below as appropriate.

Ovid Medline

6. [last line of search - your line number will be different]
7. exp animals/ not humans/ 
8. 6 not 7

Commonly used commands in Ovid Medline. 

Some databases, such as Ovid MEDLINE(R) ALL, include many thousands of non-indexed records and pre-print publications. These new records flood in from electronic publications and there is a time lag before they can be fully indexed or described. The records received from publishers are basic and don't (yet) include subject headings. Of course these non-indexed records include the latest research, so we don't want to lose them.

• They do not include subject headings - so we have to use text word searches to find them
• They do not include indexing for human or animal studies - so we lose ALL of the non-indexed records if we 'limit to humans'.
• They do not include indexing for age ranges or gender or most other automated limits - so we lose ALL of the non-indexed records if we use those limits

There are the only two limits we recommend:

• English language - works for most old and new records. However some records from the 1980s and 1990s don't index language at all. 
• date range - these are publication dates included in the basic record