Response to: ‘Associations of regular glucosamine use with all-cause and cause-specific mortality: causality assumptions need to be checked’ by Safiri and Mansournia

We appreciated Safiri and Mansournia for their interest and comment on our recent study.1 2 Safiri et al 1 mentioned that we did not explain the steps for the selection of confounders that have been included in our fully adjusted models. We acknowledged that due to the limited number of the words for the manuscript required by the journal, the content for the explanation for selection of confounders was not included. Actually, all confounders in our study were selected according to the published literature,3–5 and these were the most important risk factors for mortality. In total, 27 …