
Evidence Based Medicine Searching Strategies
Logic
When forming a search strategy, how you link the terms is important. Using boolean logic, the linkage term OR will expand the retrieval to include synonymous terms. The linkage term AND will limit the retrieval to sets which contain both the terms.
For this search, link the therapy search terms you have chosen with OR. 
EXAMPLE: 
(MeSH)  1 exp clinical trials/ or exp research design/ or comparative
study 
(textword)  2 (random: or blind: or mask: or efficacy or effectiveness).tw. 
(combine MeSH and textwords)  3 1 or 2 
Then, create your set with the headache/dt terms you have chosen. 
EXAMPLE: 
 4 sumatriptan/ and migraine/dt 
Finally, combine the EBM terms with the drug and headache terms using the
AND link 
EXAMPLE: 
 5 3 and 4 

