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.