Decreasing Adverse Events From Warfarin In a Community Hospital Setting

Millions of patients across the USA received warfarin to prevent and treat thromboembolism each year. Despite its effectiveness warfarin is associated with a risk of bleeding. The Joint Commission has brought attention to the safety of warfarin and challenged hospitals to “reduce the likelihood of harm associated with the use of anticoagulation therapy” as one of two new national patient safety goals for 2008. At CAMC (Charleston Area Medical Center, Charleston, WV) an anticoagulation safety task force was formed to address this challenge.

This study was initiated to document and reduce harm from warfarin at CAMC.

This is an ongoing retrospective review of inpatients that received warfarin and had an INR of ≥4.0. Variables collected included, INR values, warfarin administration (dose and frequency), comorbidities, other current medications, other laboratory values, harm level (as defined by the Institute for Healthcare Improvement), presence of major or minor bleeding, use of blood transfusions, fresh frozen plasma, or vitamin K (and dose).

During baseline period there was a 3 month average of 15.86 episodes of harm/1000 warfarin doses while post implementation 9.69 episodes of harm were noted. At baseline, of those with harm 83.7% were temporary harm in which patients required an intervention (FFP or vitamin K) and 30.2% of the critical INR's occurred when warfarin was ordered daily instead of after the result was obtained and reviewed by the physician. From baseline April-July 08 compared to Aug 08-Feb 09 the frequency of vitamin K administration for INR < 5 and no bleeding has decreased by 33% (p=0.144). Overall there were 4.15% critical INR's before compared to 0.88% after implementing improvements representing a 79% improvement.

Baseline data suggested a need for improvement in the safety of warfarin. Implementation of education, order sets (warfarin administration, warfarin reversal, physician pocket cards, and inpatient to outpatient handoff order sets, and warfarin workflow) and drug/drug interaction alerts to reduce adverse events. This study showed a decrease in the episodes of harm and the percent of critical INR's. It is estimated that the annual cost savings (RN time to treat critical INR's, excluding nursing time to administer vitamin K, and length of stay from complications of treatment) was $50,445.

No relevant conflicts of interest to declare.