Study design

We conducted a structured retrospective chart review of all adult patients receiving 4F-PCC from when it became available to our hospital in 2015 through 2016. Data were obtained from electronic medical records reviewed in Cerner PowerChart, the centralized clinical database for our hospital. Three independent reviewers extracted data to ensure reliable capturing; any discrepancies were resolved via discussion amongst the reviewers. Medical record review was consistent with the recommendations of Gilbert et al. [12], as well as that of Kaji et al. [13]. Our study also followed the Strengthening of Reporting of Observational Studies in Epidemiology (STROBE) reporting guidelines for cross-sectional studies (http://www.equator-network.org/reporting-guidelines/strobe/). Because of its retrospective design, this study was approved by our institutional review board (2017-4079) with waiver of informed consent.