Table 1.

Evidence search strategy (S3-guidelines on allergy prevention)

Database/source	Search step/search terms	Hits
MEDLINE	(((((((“Allergy and Immunology“[Mesh]) OR “Asthma“[Mesh]) OR „Rhinitis, Allergic, Seasonal“[Mesh]) OR „Dermatitis, Atopic“[Mesh])) OR (Asthma OR Allergy OR allergic OR atopic OR hay fever OR dermatitis OR eczema OR rhinitis))) AND (((prevention OR risk factor OR epidemiology))) AND ((Clinical Trial[ptyp] OR Controlled Clinical Trial[ptyp] OR Meta-Analysis[ptyp] OR Randomized Controlled Trial[ptyp] OR systematic[sb]) AND (“2008/05/01“[PDat] : “2013/05/31“[PDat])) LIMITS: Human	2,517
	Allergy AND Medi* AND Prevention Asthma AND Medi* AND Prevention	329
Cochrane	Asthma	165 in “Cochrane Reviews“ und 92 in „Other Reviews“
	Allergy	37 in “Cochrane Reviews“ und 7 in “Other Reviews“
Surveys of experts		70
References of overview articles		67

RCT, randomized controlled study