Abstract
Although the effects of hospital volume on mortality have been studied in other procedures, data on total joint arthroplasty (TJA) are limited. Furthermore, mortality rate among surgical patients with early major complications has become an important patient safety indicator and has been shown to be an important driver of mortality in certain operations. Our objective was to examine the effect of hospital volume on early complications and in-hospital mortality rate after TJA.
A total of 5,396,644 patients undergoing elective, unilateral TJA between 2002 and 2011 were identified using the Nationwide Inpatient Sample database. Hospitals were divided by annual volume into tertiles. Major complications associated with postoperative mortality were identified. Risk-adjusted mortality (RAM) was calculated to adjust for hospital case mix.
For THAs performed at high-volume centers, RAM was significantly lower (0.03% vs 0.41%, P < .05, high vs low volume) with lower prevalence of major complications (2.2% vs 3.3%, P < .05, high vs low volume). We observed similar results for TKA where RAM was lower (<0.01% vs 0.06%, P < .05, high vs low volume). Major complications, however, were not significant (1.4% vs 1.5%, P < .83). Pneumonia was the most prevalent complication for THA (1.5% vs 0.9%, P < .05, high vs low volume) and TKA (0.9% vs 0.5%, P < .05 high vs low volume).
Hospital volume appears to drive a large proportion of the variation in early in-hospital mortality after TJA. This variation does not seem to be explained by hospital case mix and rather by the higher prevalence of major postoperative complications in lower volume institutions.