We performed a post hoc analysis of prospectively collected data from six previously published randomized trials of airway management conducted by the Pragmatic Critical Care Research Group in the United States (1 (link), 10 (link)–14 (link)). The trials enrolled 979 patients undergoing nonelective TI in the ED or ICU between February 2014 and May 2018. We analyzed deidentified data in the trial datasets from patients who were intubated using DL with a Macintosh blade size 4 or 3 on the first attempt; we excluded patients intubated with smaller blade sizes or those for whom data on blade size was missing or a video laryngoscope used on first attempt. Individual trials were approved by the institutional review board (IRB) of each respective site with documented waiver of informed consent by respective site IRB (1 (link), 10 (link)–14 (link)). Studies were carried out per the ethical standards of the responsible committee on human experimentation and with the Helsinki Declaration of 1975. Details are documented in individual manuscripts. This study was deemed a secondary analysis of a deidentified data set of prior studies and no IRB review was deemed necessary by the IRBs (and thus no number was assigned) as it did not fall under the board’s guidelines as human subjects research.