No abstract

Data was collected from National Inpatient Sample (NIS). NIS is part of Healthcare Cost and Utilization Project (HCUP) databases and is made possible by a Federal-State-Industry partnership sponsored by the Agency for Healthcare Research and Quality (AHRQ). The NIS is derived from all States for national estimates of healthcare utilization, cost and outcomes (9) . Since NIS is compiled annually, the data can be used for analysis of disease trends over time. The study was deemed exempted from Institutional Review Board approval given the de-identified nature of the NIS database and public availability.