Letter the editor: serious methodological concerns about a recently published meta-analysis on oxygen therapy. - Klitgaard, Thomas Lass; Schjørring, Olav Lilleholt; Nielsen, Frederik Mølgaard; Meyhoff, Christian Sylvest; Barbateskovic, Marija; Wetterslev, Jørn; Perner, Anders; Rasmussen, Bodil Steen (Journal of Intensive Care, 2021)