Efficacy and effectiveness of sublingual immunotherapy for grass pollen allergy: Reply to the letter of Marcucci F

Abstract

I have read the letter of Marcucci [ [1] Efficacy and effectiveness of sublingual immunotherapy for grass pollen allergy: letter of Marcucci F Google Scholar ] with great attention. First of all, It could be useful to underline that the criticized paper is an editorial, not surprisingly written by an editor, and, in particular, an interview as explicitly stated. It dealt with an important systematic review and meta-analysis of clinical trials of sublingual immunotherapy for grass pollen allergy [ [2] Corrao S. Di Bona D. Di Lorenzo G. Efficacy but not effectiveness of sublingual immunotherapy for grass pollen allergy: time to avoid waste in health-care expenditure. Eur J Intern Med. Oct 2015; 26: 561-562 Abstract Full Text Full Text PDF PubMed Scopus (2) Google Scholar ], published in one of the leading journals of medicine. The editor of JAMA himself had thrown a “caveat emptor” [ [3] O'Malley P.G. Caveat emptor on sublingual immunotherapy. JAMA Intern Med. Aug 2015; 175: 1310 Crossref PubMed Scopus (3) Google Scholar ], just after having published and pointed out the results of the meta-analysis above mentioned. Therefore, these preliminary remarks could be enough to bring down every criticism. However, the letter of Marcucci may be very useful to go into evidence-based methodological issues thoroughly. I have no doubt about the good faith of Marcucci so that I would like to explain to the readers the different types of biases that characterize an opinion-based view. A physician specialized in a particular field may be influenced by clinical practice, specialized literature, and specialistic medical meetings. All that grows up strong personal belief so that a balanced analysis may be blinded. This seems the case. Indeed, criticisms regard the interview at issue but not any actual point of the meta-analysis. Another point is a biased view of the evidence-based principles themselves. For example, a guideline is cited but the recalled statement is published before of the meta-analysis in question. Thus, no guideline can be claimed if it is dated. Moreover, the other two references are dated as well. Another matter may be the difference between efficacy and effectiveness. A slight treatment benefit in the symptom score means that no effectiveness was found out. Effectiveness refers to clinical relevance while efficacy prevalently refers to statistical significance. Finally, it is particularly naïve to think that a meta-analysis may be unofficial. The Cochrane collaboration has carried out and carry on a meritorious action. However, systematic reviews with meta-analyses are published in many journals. Thus, any meta-analysis, including a Cochrane one, has to be criticized through critical appraisal without any prejudice. For all these reasons, criticisms of Marcucci on the editorial/interview seem sui generis since it had to be addressed to the article published in JAMA [ [4] Di Bona D. Plaia A. Leto-Barone M.S. La Piana S. Di Lorenzo G. Efficacy of grass pollen allergen sublingual immunotherapy tablets for seasonal allergic rhinoconjunctivitis: a systematic review and meta-analysis. JAMA Intern Med. Aug 2015; 175: 1301-1309 Crossref PubMed Scopus (78) Google Scholar ]. In conclusion, the actual question is, may therapeutical choices be only a matter of faith?