Footnotes

• Twitter @dangessner

• Contributors DG helped design the study, collected and analyzed data, drafted and revised the initial manuscript, and reviewed and approved the submitted manuscript. BCHT revised the initial manuscript and reviewed and approved the submitted manuscript. J-LH helped design the study, analyzed data, revised the initial manuscript, and reviewed and approved the submitted manuscript.

• Funding The study was funded by the Stanford University Department of Anesthesiology, Perioperative, and Pain Medicine. The Stanford REDCap platform (http://redcap.stanford.edu) is developed and operated by Stanford Medicine Research IT team. The REDCap platform services at Stanford are subsidized by (a) Stanford School of Medicine Research Office, and (b) the National Center for Research Resources and the National Center for Advancing Translational Sciences, National Institutes of Health, through grant UL1 TR001085.

• Competing interests None declared.

• Provenance and peer review Not commissioned; externally peer reviewed.