Buying an INR Machine and Checking Your Blood Anticoagulation
Coumadin (warfarin) has to be monitored on a routine basis to ensure that the patient is receiving the correct dosage. Home monitoring is one of a few options for patients to consider while they are using warfarin for anticoagulation therapy. They will need to have blood checks done frequently, starting daily, but as the patient's blood levels stabilize, the checks may become further apart.
These checks are done to measure international normalized ratio (INR), a number that represents the amount of time your blood takes to clot (prothrombin time, or PT).
There are currently three different methods for checking INR:
- The traditional way: The patient goes to his or her doctor's office or to an anticoagulation clinic. Blood is drawn from a vein and sent to a lab. Results can take anywhere from 1-2 hours to 1-2 days to return since some places use third-party labs for this test. Once the results are received, the patient will be notified of their INR and adjusted warfarin dose.
- The physician's office using a point-of-care machine: The patient goes to his or her doctor's office or anticoagulation clinic. A fingerstick is done, and a drop of blood is placed on a small machine. In a few minutes, the machine shows the INR and the dose is adjusted.
- Self-testing: A patient purchases a point-of-care machine for home use. The patient performs his or her own fingerstick and blood test. The INR is shown in a few minutes. The patient reports the INR to his or her doctor for dose adjustments. In European countries, it is becoming increasingly common for patients to self-adjust warfarin dosage. At this time, this is highly uncommon in the US and Canada. It is not recommended to change your own dosages—always consult your doctor first.
This article will provide you with some great information about the pros and cons of self-testing and where to purchase the necessary machine.
Disclaimer: Please speak with your doctor about the best INR monitoring option for you. Note that I am not a medical professional. I was diagnosed with a pulmonary embolism and factor V Leiden in 2008, and I have attended support groups and researched the topic extensively.
Advantages of Testing at Home
While doctors and anticoagulation clinics provide excellent care, testing at home can really benefit some patients.
- It is more convenient. There are no trips to the doctor for blood work. This saves you gas and driving time. For patients who are driving long distances to see a doctor, or who do not have transportation, this will be a huge help. If a warfarin user travels a lot or works an unusual schedule, INR scheduling can be very problematic. Home-testing can be done anytime and anywhere.
- Patients often feel empowered. This is a great feeling for many people who feel tethered by their medication regimen. It allows the patient to more easily track INR when there are medication, diet, or other changes rather than trying to schedule an appointment when something unexpected happens.
- You only need a drop of blood. Point-of-care monitors only use a small drop of blood from a fingerstick. This will be a large relief to anyone who has problems with IV blood draws.
Disadvantages of Testing at Home
- Home INR machines do not work well for people with APS (antiphospholipid syndrome). The antiphospholipid antibodies can disrupt the phospholipid in the prothrombin time (PT) reagent and cause an incorrect INR reading. If you have APS and want to use a home INR machine, please read the literature at the APS Foundation and discuss with your physician. Occasionally, home testing can be done after carefully comparing home INR readings with venous blood draw readings.
- It may not work well for patients with INRs over 4.0. The National Blood Clot Alliance notes that this is a problem for both venous blood draws and point-of-care machines.
Is Testing INR at Home Reliable?
A 2008 study found that home-testing is as reliable as testing done by a doctor. This study mirrors the results of numerous other studies that show testing at home improves warfarin management by more quickly identifying patients who are out of INR range and engaging patients in their own care.
You may be a good candidate for home INR testing if:
- You are compliant with your anticoagulation therapy.
- You have the manual dexterity to do the fingerstick and get the blood drop on the test strip or you have someone to help you with this.
- Your doctor or anticoagulation clinic is open to home INR testing and will work with you to design an effective home INR treatment plan
- You meet your insurance provider's coverage requirements for home INR testing (varies by company) or can pay out of pocket for testing equipment and supplies.
Many insurance plans, including Medicaid and Medicare, will cover the cost of home INR testing for some (but not all) conditions that require anticoagulation therapy. Speak with your insurance provider for information about coverage. Many machine distributors may also be able to help you understand your insurance coverage and options. Take a look at distributor sites below for assistance with insurance questions. According to ClotCare, home INR machines cost $1,000-$2,000 and test strips are around $12 each without insurance.
Manufacturers and Suppliers
- PTINR.com | Home INR Monitoring
- mdINR - Manage Your Coumadin Patients | INR Home Testing
With mdINR, doctors can manage their coumadin clients and patients can take charge of their inr testing.
- Philips Home INR
Coumadin level monitoring for Doctors and Patients taking Coumadin or other generic warfarin anticoagulation medication.
- CoaguChek - Know your INR value
A PT/INR tester for home use, the CoaguChek® gives accurate anticoagulation results in less than a minute.
What Are the Next Steps?
If you are interested in home INR management, consult your doctor that currently manages your anticoagulation. Your doctor will still be highly involved in your care, so it is vital that he or she has a say in your decision to switch to home care.
The next step will be to get a prescription from your doctor and to speak with your insurance provider. I recommend checking out the sites that I have provided as well as going to the Daily Strength Pulmonary Embolism Support Group online to ask questions because many members there have purchased and used a home INR machine. They can recommend suppliers and give you reviews of the customer service they have received.
Once you have received your home care machine, please share your experiences in the comments section below. I look forward to hearing from everyone!