Table 1.

Example search strategy.

Step	Search
1	Echinacea.mp. or exp Echinacea/
2	coneflower.mp.
3	Black Sampson.mp.
4	1 or 2 or 3
5	(randomized controlled trial or controlled clinical trial).pt. or randomized.ab. or randomized.ab. or placebo.ab. or drug therapy.fs. or randomly.ab. or trial.ab. or groups.ab.) not (exp animals/ not humans.sh.)
6	4 and 5
7	Remove duplicates from 6
8	limit to controlled, randomized human RTI studies