The problem with warfarin (at least, until the alternatives arrive) is monitoring its efficacy – usually done with regular measuring of the INR. Dosing warfarin varies greatly between patients, days, diets, and other medications, which definitely makes it more difficult. Previously, patients would have to come in to a pathology lab to have their blood taken, but now point of care devices have made testing INR easier, meaning that patients can take it more frequently – but these devices can be more accurate.
Which brings us to a common question in medicine – easier and less accurate, or harder and more accurate?
The New England Journal of Medicine looked at 2922 patients, either testing themselves at home weekly, or coming into clinic monthly, and compared major event rates (stroke, major bleeding events, or death). Results were…similar. To summarise:
- time to first primary event was not significantly different (statistically)
- self testing group
- higher time in target INR range
- higher patient satisfaction
- more minor bleeding episodes