Background: Anticoagulation with vitamin K antagonists reduces major thromboembolic complications in at-risk patients. With portable monitoring devices, patients can conduct their own international normalized ratio testing and dose adjustment at home.
Purpose: To determine whether patient self-testing (PST), alone or in combination with self-adjustment of doses (patient self-management [PSM]), is associated with a reduction in thromboembolic complications and all-cause mortality without an increase in major bleeding events compared with usual care.
Data sources: MEDLINE and the Cochrane Central Register of Controlled Trials.
Study selection: Studies published in English from 1966 to October 2010 that enrolled outpatient adults receiving long-term (>3 months) oral anticoagulant therapy and that compared PST or PSM with care in a physician's office or an anticoagulation clinic were included.
Data extraction: Two investigators reviewed each article. Three investigators extracted data from articles that met inclusion criteria by using standardized data abstraction forms. Studies were assessed for quality, and the overall strength of evidence was rated for each clinical outcome.
Data synthesis: Twenty-two trials, with a total of 8413 patients, were included. In one half of the trials, fewer than 50% of potentially eligible persons successfully completed the training and agreed to be randomly assigned. Patients randomly assigned to PST or PSM had lower total mortality (Peto odds ratio [OR], 0.74 [95% CI, 0.63 to 0.87]), lower risk for major thromboembolism (Peto OR, 0.58 [CI, 0.45 to 0.75]), and no increased risk for a major bleeding event (Peto OR, 0.89 [CI, 0.75 to 1.05]). The strength of evidence was moderate for the bleeding and thromboembolism outcomes but low for mortality. Eight of 11 trials reported that patient satisfaction, quality of life, or both was better with PST or PSM than with usual care.
Limitations: In one half of the trials, fewer than 50% of the potentially eligible patients were randomly assigned. Only 5 trials were considered high quality, and only 2 were conducted in the United States. No studies addressed whether PST or PSM is safe during the high-risk initiation phase.
Conclusion: Compared with usual care, PST with or without PSM is associated with significantly fewer deaths and thromboembolic events, without increased risk for a serious bleeding event, for a highly selected group of motivated adult patients requiring long-term anticoagulation with vitamin K antagonists. Whether this care model is cost-effective and can be implemented successfully in typical U.S. health care settings requires further study.
Primary funding source: U.S. Department of Veterans Affairs Health Services Research and Development Service.