2.1 Study design
This is a retrospective analysis of the National Inpatient Sample (NIS)
database. The NIS is reflective of all hospital admissions in the United
States. It serves as an essential tool for analyzing the trends in
outcomes and costs of healthcare procedures. More details regarding the
database are available online.5 Given the data from
NIS are de-identified, this study was exempt from Institutional Review
Board review. Consent statement and clinical trial registration are not
applicable for this study.