Start developing a search strategy by identifying the key words and concepts within your research question. The aim is to identify the words likely to have been used in the published literature on this topic.
For example: What are the key infection control strategies for preventing the transmission of Methicillin-resistant Staphylococcus aureus (MRSA) in aged care homes.
Treat each component as a separate concept (there are usually between 2-4 concepts).
For each concept list the key words derived from your research question, as well as any other relevant terms or synonyms that you have found in your preliminary searches. Also consider singular and plural forms of words, variant spellings, acronyms and relevant index terms (subject headings).
|Search concept 1||Search concept 2||Search concept 3|
|infection control||methicillin resistant staphylococcus aureus||aged care homes|
|infection prevention||meticillin resistant staphylococcus aureus||nursing homes|
|MESH TERMS||MESH TERMS||MESH TERMS|
|exp Infection Control/||Methicillin-resistant Staphylococcus aureus/||homes for the aged/|
As part of the process of developing a search strategy, it is recommended that you keep a master list of search terms for each key concept. This will make it easier when it comes to translating your search strategy across multiple database platforms.
Boolean operators are used to combine the different concepts in your topic to form a search strategy. The main operators used to connect your terms are AND and OR. See an explanation below:
Example: nursing home OR aged care home
Example: nursing home AND infection control
Example: aged care homes NOT residential homes will retrieve all the results that include the words aged care homes but don't include the words residential homes. So if an article discussed both concepts this article would not be retrieved as it would be excluded on the basis of the words residential homes.
See the website for venn diagrams demonstrating the function of AND/OR/NOT:
By using a truncation symbol you can capture all of the various endings possible for a particular word. This may increase the number of results and reduce the likelihood of missing something relevant. Some tips about truncation:
There are also wildcard symbols that function like truncation but are often used in the middle of a word to replace zero, one or more characters.
See the Database search tips for details of these operators, or check the Help link in any database.
For words that you want to keep as a phrase, place two or more words in "inverted commas" or "quote marks". This will ensure word order is maintained and that you only retrieve results that have those words appearing together.
Example: “nursing homes”
There are a few databases that don't require the use of quote marks such as Ovid Medline and other databases in the Ovid suite. The Database search tips provides details on phrase searching in key databases, or you can check the Help link in any database.
Many databases use subject headings to index content. These are selected from a controlled list and describe what the article is about.
A comprehensive search strategy is often best achieved by using a combination of keywords and subject headings where possible.
In-depth knowledge of subject headings is not required for users to benefit from improved search performance using them in their searches.
Advantages of subject searching:
Note: Subject headings are often unique to a particular database, so you will need to look for appropriate subject headings in each database you intend to use.
Subject headings are not available for every topic, and it is best to only select them if they relate closely to your area of interest.
The MeSH thesaurus provides standard terminology, imposing uniformity and consistency on the indexing of biomedical literature. In Pubmed/Medline each record is tagged with MeSH (Medical Subject Headings).
The MeSH vocabulary includes:
Sources for a 'gold set' may include:
The papers in your 'gold set' can then be used to help you identify relevant search terms
The 'gold set' will also provide a means of testing your search strategy
A search strategy is the planned and structured organisation of terms used to search a database.
An example of a search strategy incorporating all three concepts, that could be applied to different databases is shown below:
You will use a combination of search operators to construct a search strategy, so it’s important to keep your concepts grouped together correctly. This can be done with parentheses (round brackets), or by searching for each concept separately or on a separate line.
The above search strategy in a nested format (combined into a single line using parentheses) would look like:
("infection control*" OR "infection prevention") AND ("methicillin resistant staphylococcus aureus" OR "meticillin resistant staphylococcus aureus" OR MRSA) AND ( "aged care home*" OR "nursing home*")