RESULTS All INR results will be forwarded to the community physician's office and will thereby be recorded as data to determine the proportion of values in therapeutic range. Statistical calculations will be done according to accepted practices for analysis of cross-over studies by a researcher with experience in statistical analysis. Patients will be given a structured treatment-related quality of life survey after the before and after the PSM phases and will explore topics of general treatment satisfaction, self-efficacy, strained social network, daily hassles, and distress. The survey consists of 32 questions and has been previously described and validated.4 Other outcomes including office visits utilized for issues of PSM, and complications of sub- or supra-therapeutic coagulation will be recorded. Secondary outcomes are not expected to be significant due to the limited power of the study.