Intravenous Acetaminophen May Be Associated with Reduced Odds of 30-Day Readmission after Total Knee Arthroplasty.

The purpose of this study was (1) to evaluate 30-day readmission rates in total knee arthroplasty (TKA) patients who either received intravenous (IV) or oral (PO) acetaminophen (APAP) perioperatively and (2) to extrapolate the potential annual cost savings on the national level. This was a review of 190,691 TKA recipients between the years 2012 and 2015 who received either IV ( n  = 56,475) or PO APAP ( n  = 134,216). All-cause readmissions that occurred between patient discharge and 30 days postdischarge were recorded. Continuous and categorical variables were evaluated using t -test and chi-square test, respectively. A logistic regression analysis was conducted to assess the effect of IV APAP on 30-day readmission. We also performed a literature review on 30-day readmission rates and risk prediction tools for TKA and correlated these with our findings. In addition, we extrapolated potential cost savings on the national level. The readmission rate was 0.04% in the IV and 0.14% in the PO APAP cohort (69% decreased risk; odds ratio = 0.31; 95% confidence interval = 0.20-0.47; p  < 0.001). The readmission rate in this patient population appears to be markedly lower, when compared with previous reports. This reduction in readmissions may potentially result in $160 million savings per year. The use of IV APAP in TKA patients resulted in lower readmission rates, which may be valuable in clinical decision making by surgeons and health care administrators looking to lower costs of care.