Increased frequency of prothrombin time testing, facilitated by patient self-testing (PST) of the international normalized ratio (INR), can improve the clinical outcomes of oral anticoagulation therapy (OAT). However, oversight of this type of management is often difficult and time consuming for health care professionals. Ryan and colleagues reported on the first randomized controlled trial of an automated direct-to-patient expert system, enabling remote and effective management of patients on OAT. A prospective, randomized controlled cross-over study was carried out to test the hypothesis that supervised PST using an internet-based, direct-to-patient expert system could provide improved anticoagulation control to that provided by an anticoagulation management service (AMS). During the six months of supervised PST, patients measured their INR at home using a portable meter and entered this result along with other information onto the internet web page. Patients received instant feedback from the system as to what dose to take and when the next test was due. During the routine care arm, patients attended the AMS at least every 4-6 weeks and were dosed by the anticoagulation pharmacist or physician. The primary outcome variable was the difference in the time in therapeutic range (TTR) between both arms. There were 162 patients enrolled (male 61.6%, mean age 58.7 years);132 patients (81.5%) completed both arms. TTR was significantly higher during PST management (median 74%) than during AMS management (median 58.6%), z = 5.67, p<0.001.

WHAT THE STUDY COULD MEAN TO YOU AS A HEALTH CARE PROVIDER: The authors concluded that the use of an internet-based, direct-to-patient expert system for the management of PST improved the control of OAT compared with AMS management.

WHAT THE STUDY COULD MEAN TO YOU AS A PATIENT: If you perform self-management skills to control any chronic illness, quick feedback could help improve your performance. It is anticipated that more management programs will include similar methods for providing information back to patients in the future.

F Ryan et al. Randomised controlled trial of supervised patient self-testing of warfarin therapy using an internet based expert system. Journal of Thrombosis & Haemostasis, May 30, 2009.