Patient Centric App Review Series

While newer anti-coagulants offer the opportunity to avoid regular INR testing, these newer medications are not necessarily superior to warfarin and are much more expensive.

In select, well-motivated patients, home warfarin testing may be an appropriate choice and the app store offers options to help patients remember dosage and INRs over time.

OATBook is an elegant and simple tracking app for individuals on Oral Anticoagulant Therapy (OAT) to record their INRs and warfarin doses. It was developed by an end-user who resides in the United Kingdom.

On the main screen the user can enter a daily INR (next to the drop), warfarin dosage, notes and the time for the next INR testing.

Although easy to use, there is no built in support on the app nor on the website. It took the reviewer some trial and error to discover it was necessary to swipe from right to left to input data.

With values preset on the settings page, if the INR is too high the user is warned and given the option to call the doctor’s office.

If the “call the clinic” button is pushed, the user can make the phone call from the app and the screen shows the medication dose last taken.

Healthcare Goals:

  • This app is to help patients monitor and record INRs. The app can be set up with an alert to remind patients to take their medication and check the INR.

Evidence to Support Goals:

  • In select, appropriate patients on warfarin therapy, self-monitoring and dosage self-adjusting has been shown to lower complications.


  • $2.99


  • Elegant in appearance
  • Can record alternate day dosages
  • Alerts user to take medication and check INR
  • Physician telephone number pops up if INR is out of range
  • Quick response on developer’s Twitter support site
  • Ability to add notes


  • No support immediately available on the app or on-line.
  • Support is through the developer’s Twitter site.

Suggested Additional Features:

  • Log of INR’s with warfarin doses and email capability for the log
  • Bar graph of INR’s
  • List of common foods and medications that interfere with warfarin effect


  • Despite the “first time” walk through, entering data was not immediately intuitive; however, once the user understands how to input data, it is a straightforward method of monitoring a dangerous medication that works most effectively and safely within a narrow therapeutic window.
  • Makes self-monitoring of warfarin easier for motivated and app-savvy patients.

Bottom Line:

  • This is a good app to consider prescribing in select, motivated patients who want to self-monitor their warfarin therapy.

iTunes Link

This post does not establish, nor is it intended to establish, a patient physician relationship with anyone. It does not substitute for professional advice, and does not substitute for an in-person evaluation with your health care provider. It does not provide the definitive statement on the subject addressed. Before using these apps please consult with your own physician or health care provider as to the apps validity and accuracy as this post is not intended to affirm the validity or accuracy of the apps in question. The app(s) mentioned in this post should not be used without discussing the app first with your health care provider.