Level 2: Mid-level evidence
For patients on long-term oral anticoagulation therapy, use of point-of-care devices is associated with lower rates of death and major thromboembolic events compared with laboratory determinations of international normalized ratio (INR), based on a systematic review of 16 randomized trials (Open Medicine. 2007;1; full text available online free of charge at: www.openmedicine.ca/article/view/77/75, accessed June 6, 2008). Trials included in the systematic review had methodologic limitations: Only three trials defined how thromboembolic events were diagnosed, only five trials had blinded outcome assessors, dropout rates were 10%-28% after randomization to point-of-care device in seven of 11 trials, and point-of-care-device patients had a higher frequency of INR testing and received much more intensive education on therapy management.
Point-of-care devices were associated with better INR control. Comparing point-of-care devices vs. laboratory INR testing, mortality was 3% vs. 5.2% (nine trials with 2,563 patients; P=.01, NNT 46), and rate of thromboembolic events was 2.1% vs. 3.6% (15 trials with 4,774 patients; P=.0004, NNT 67). There was no significant difference in the rates of major hemorrhage in a meta-analysis of 15 trials with 4,708 patients.