This document addresses the clinical indications for use of battery-operated prothrombin time self-monitoring devices, also referred to as International Normalized Ratio (INR) devices, used by individuals in the home to monitor blood-clotting rates.

Clinical Indications

Medically Necessary:

Home prothrombin time self-monitoring using an INR device is considered medically necessary for an individual who meets all of the following criteria:

1. Requires long term (greater than one year) anticoagulation with warfarin; and
2. Requires at least weekly determinations of INR values; and
3. The treating physician prescribes the self-monitoring device and home testing.

Not Medically Necessary: 

Home prothrombin time self-monitoring is considered not medically necessary for an individual who does not meet the above criteria.