Helping manage anticoagulation patients for over 12 years


Rosendaal method for patient TTR calculations available in Excel template

2/18/2013 - The Rosendaal method1 of calculating therapeutic time in range (TTR) has become one of the more popular methods of determining how well a patient is maintaining their INR test results.

However, the calculation used to determine TTR using this method is more difficult than the traditional method of calculating the percent of tests within range. It's simple to just count up the number of tests within range, and divide by the total number of tests. When you start comparing previous INR values to the current result, and determining the number of days in between, it gets more complicated.

We tried to provide an example of this calculation on our definitions page within the software. However, we still get questions about how the equation works at a detailed level.

We recently completed development of a simple Excel template, where you can enter your patient's test dates and INR values, and it will calculate the traditional and Rosendaal method for you.

Click here to download the template >>>

If you have multiple patients that you'd like to analyze all at once, using these TTR calculations, this template will not meet your long term needs. Consider signing up for our INR Pro Reporting System. If you can download your patient data from your current INR tracking system, and get it into an Excel format, then you can upload all your patient data into our database. This will not only give you access to the Rosendaal calculation reports across all patients, but you can also run many of the reports we have available in our patient management system, without dropping your existing management program.

1Quality assessment of anticoagulation dose management: comparative evaluation of measures of time-in-therapeutic range; Schmitt L, Speckman J, Ansell J.

INR Pro - patient anticoagulation tracking systemIf you would like to take advantage of these features with INR Pro, try our demo, or contact us for more information.