Hospital volume and inpatient mortality outcomes of total hip arthroplasty in the United States.

The purpose of this study was to examine the effect of hospital volume on outcomes for primary and revision total hip arthroplasty (THA). The Nationwide Inpatient Sample database was used to identify our patient set. These data include a sample of non-Medicare and Medicare patients who are unique to this study, increasing external validity compared with other studies. Outcome variables examined included in-hospital mortality and prolonged length of stay (PLOS). Primary THA mortality was 0.16% in the highest volume quartile and 0.29% in the lowest volume quartile (P < .001). The rates of PLOS showed improved outcomes in the highest volume hospitals. Similar trends were found for revision THA, with an in-hospital mortality of 1.20% for lowest volume hospitals and 0.48% for highest volume hospitals (P < .001). Hospitals with higher volume had superior inpatient outcomes mortality, PLOS, and discharge disposition for THA and revision arthroplasty.