Efficacy and effectiveness of sublingual immunotherapy for grass pollen allergy

I was very surprised by the letter “Efficacy but not effectiveness of sublingual immunotherapy for grass pollen allergy: time to avoid waste in health care expenditure” by Corrao et al. published in the European Journal of Internal Medicine [ ]. In fact, the statements by the authors on sublingual immunotherapy (SLIT) have no ground. They, based on a recent negative meta-analysis on grass pollen SLIT tablets for seasonal rhinitis published by the other two authors of this letter [ ], in the final paragraph state that “patients should be informed about the low a priori chances of clinical improvement”. This is in complete contrast with a large number of positive meta-analyses globally defining SLIT as a treatment supported by 1A level of recommendation according to EBM criteria, as accepted in international guidelines [ ]. This was acknowledged by the European Medicines Agency (EMA) and Food and Drug Administration (FDA), that recently authorized the use of grass pollen tablets to treat seasonal rhinitis in Europe and U.S. [ , ]. Corrao and colleagues oppose to this bulk of evidence their findings from an unofficial meta-analysis (it was not published in the site of the Cochrane database systematic reviews), declaring that “our findings support no longer that SLIT costs are paid by public welfare”. The different weight of a single meta-analysis compared to the full evidence by the literature must be clear to the reader.