Randomized Trial of Interventions to Improve Warfarin Adherence

Randomized Trial of Interventions to Improve Warfarin Adherence

The purpose of this research study is to see if a lottery which provides the opportunity to win money, a reminder system using a "Med-eMonitor", or the combination of both might be useful in helping patients to achieve better control of their anticoagulation therapy. Selection for the arms of the study is randomized by the study computer. Some will participate in the daily lottery only, some with the reminder system only, some with the reminder system and the daily lottery, and some with neither the lottery nor the reminder system.

Eligible subjects will be enrolled in one of the 4 arms of the RCT and followed for 6 months, with the primary outcome of out-of-range INRs. Subjects will be given a Med-eMonitor to connect to their home phone line. For all subjects, these will be used to measure daily adherence. Subjects in the incentive group will be eligible for a daily lottery prize only if, prior to the lottery being resolved, their adherence device has registered adherence to their prescribed warfarin regimen. Subjects in the MM group will have the reminder/feedback features of the Med-eMonitor turned on to provide reminders to take their warfarin as prescribed and standardized messages that will be used to provide feedback in response to their adherence. Subjects in the combined group will be exposed to both the lottery and the activated Med-eMonitor. This trial is a randomized controlled trial.

Both men and women who are at least 18 years of age and have been prescribed anticoagulation medication are eligible to participate.

Key Inclusion Criteria

The study population will include all patients at the study sites who:

1. are in the maintenance phase of their warfarin treatment (defined using the standard method as the period of time following 2 consecutive visits, at least 7 days apart, of stable target INR after initiation of the drug)
2. whose providers indicate are expected to stay on treatment for at least 6 months
3. have a target INR of 2 to 3.5
4. had at least one INR out of the participant's target range within 90 days prior to enrollment (excluding the baseline visit) and/or INR at the baseline visit was below the participant's target range
5. have a working analog telephone line.

Of note, patients do not have to be within their target INR range to enroll; we specifically want to include those who are below the target range at the time of study entry because they may be the patients most likely to be non-adherent.

Key Exclusion Criteria Patients will be excluded if they do not meet the above inclusion criteria,

1. have an INR at screening above the target range
2. are less than 18 years of age and cannot or will not give consent
3. cannot read above a 6th grade reading level
4. are enrolled in a clinical trial of warfarin therapy
5. are unable to adequately follow study procedures