Warfarin for thromboprophylaxis following total joint arthroplasty: are patients safely anti-coagulated?

The purpose of this study was to investigate whether any correlation exists between INR level at discharge and postoperative complications or readmission rates. From 2010-2011, INR levels on discharge, complications and readmissions within 30 days were recorded on 441 patients undergoing joint arthroplasty. Eighty percent (352 of 441) patients had a subtherapeutic INR level at discharge. The overall complication rate was 15% with an 8.6% readmission rate. A supratherapeutic INR level at discharge was associated with both higher readmission rate as well as increased number of complications (P<0.048). Most patients taking warfarin are nontherapeutic at the time of discharge; notably, a supratherapeutic INR places patients at risk for increased complications and readmissions rates following surgery.