The study of Moro et al1 deals with the interesting question of whether there is any treatment that may prevent the development of allergy. Their main outcome is atopic dermatitis, where a group comparison between maltodextrin (placebo) and galacto/fructo‐ oligosaccharides (verum) showed an exact p value of 0.014, as reported in fig 2. I assume that they used a two‐sided test for the cumulative incidence of atopic dermatitis, where a single‐sided test may have been more appropriate, leading eventually to a p value of 0.008.
Showing the distribution of the Scoring Atopic Dermatitis Index in both treatment groups would nevertheless be interesting, as there is a high chance of confounding using inappropriate block randomisation by genetic risk. As we have shown earlier in this journal,2 the risk by parental history of various allergic diseases is not interchangeable; in other words, a few more parents with atopic dermatitis (and/or the filaggrin gene variants) in the placebo group could also explain the observed effect. The authors have also not controlled for vitamin D supplementation, which has now been found in four independent studies to be associated with later allergy.3
Apart from that, the study raises some ethical questions. According to current law in Germany, advertisement of bottle feeding is prohibited without showing the alternative of breast feeding. In my opinion, a scientific study report also needs to clearly state that the investigators have (1) promoted the benefits and advantages of breast feeding; (2) facilitated breast feeding; (3) explained potential negative consequences of bottle feeding; and (4) detailed the difficulty in reversing any decision against breast feeding. As the mean age of the first bottle feeding is only 11 days in this study, the authors need to show (eg, from the preceding year in which they obtained the data for the power calculation) that this study has not prevented breast feeding and even induced more patients with atopic dermatitis than expected under non‐observing conditions. Unfortunately, I could also not find this trial in the ClinicalTrials.gov database although registration is being endorsed by a statement from the International Committee of Medical Journal Editors. If these omissions could be clarified, the study could indicate a remarkable progress in the prevention of allergy.
Footnotes
Competing interests: None declared.
References
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