Targeted treatment of iron deficiency in prolonged critical illness: an opportunity to improve survival or not?

[...]it appears as if the primary endpoint was unknown in a considerable number of patients. [...]could the authors repeat the subgroup analysis independent of iron supplementation provided/omitted when indicated, as such is likely not a random phenomenon. [...]we compared patients with ID treated or not [2], but it does not make much sense to compare patients with ID (treated or not in the intervention arm) to patients with ID not treated, since it is the treatment of ID that is supposed to be beneficial.