Implementation of home-based international normalized ratio testing in adult patients treated with warfarin

Background and local problem: Patients who take warfarin require frequent testing of their international normalized ratio (INR) level to ensure accurate dosage. Frequent testing can be inconvenient for patients in rural settings, the workforce, the homebound, or those who travel. Patients who have a home INR monitor can test their blood remotely. Methods: To circumvent barriers to INR testing, a quality improvement project was designed to implement home INR testing in an anticoagulation clinic setting. Interventions: Patients who received a home INR monitor were compared against two usual care testing arms (laboratory and clinic testing patients) in the outcomes of time in therapeutic range (TTR), adverse events, and patient satisfaction using the Duke Anticoagulation Satisfaction Scale (DASS). Results: The DASS survey demonstrated the home testing patients had a statistically significant advantage over the clinic testing group in the subdomain of hassles and burdens (p = .048), as well as the lowest overall scores (indicating highest satisfaction) over the clinic testing group (p = .041). No patients in the home testing group had clotting or bleeding issues necessitating hospital admission. There were no significant differences between groups in the TTR analysis (laboratory 70.8%, home 68.9%, and clinic 64.5%) (p = .683). Conclusions: Home INR testing provides convenience for patients and reduces the hassles and burdens of warfarin management, leading to improved satisfaction. This engagement in self-care translates to reduced adverse events. Home INR testing can be used in warfarin patients who are highly motivated and willing to engage in their care.