Table 1.

Classification of evidence for allergen-specific immunotherapy used in the manuscript

Level of evidence

Ia Evidence from meta-analysis of randomized controlled studies Ib Evidence from at least one randomized controlled study IIa Evidence from well-designed controlled trial without randomization IIb Evidence from at least one other type of experimental study III Evidence from non-experimental descriptive studies, including retrospective, case-control studies, cohort studies with controls IV Evidence form opinions of respected authorities, based on clinical experience, or reports of expert committees

Grades of recommendations

A: Directly based on Level I evidence. A certain therapeutic intervention is strongly recommended. B: Directly based on Level II evidence or extrapolated recommendations from Level I evidence. A certain therapeutic intervention should be carefully considered. C: Directly based on Level III or IV evidence or extrapolated recommendations from Level I or II evidence. There is significant uncertainties about a certain therapeutic intervention.