Table 1:
Best evidence papers
| Author, date, journal and country, study type (level of evidence) | Patient group | Outcomes | Key results | Comment |
|---|---|---|---|---|
| Heneghan et al. (2006), Lancet, United Kingdom Systematic review with meta-analysis (level 1a) |
14 RCTs n = 3049 (adults and children) |
Effect of self-monitoring or self-management vs standard monitoring on: Thromboembolic events Major bleeding All-cause mortality Proportion of measurements within therapeutic range |
Pooled OR estimates: 0.45 (95% CI 0.30–0.68) 0.65 (0.42–0.99) 0.61 (0.38–0.98) Data could not be pooled |
This large systematic review with meta-analysis demonstrates a 55% reduction in thromboembolic events, a 35% reduction in major bleeding and a 39% reduction in all-cause mortality when patients self-monitor INR Data not presented here comparing self-management (self-monitoring plus dose adjustment) to standard management found greater reductions in the risk of thromboembolic events and all-cause mortality, but not for major bleeding. Most trials found improvements in the proportion of INR measurements within therapeutic range but owing to methodological differences these were not pooled |
| Wells et al. (2007), Open Med, Canada Systematic review with meta-analysis (level 1a) |
16 RCTs 2144.6 person-years of follow-up for treatment group, 2316.1 person-years of follow-up for control group (total 4460.7 person-years) |
Effect of self-monitoring or self-management vs conventional management on: Major haemorrhage Major thromboembolism All thromboembolism Death Percentage time within therapeutic range |
Pooled OR estimates: 0.78 (0.53–1.14) Not significant 0.51 (0.35–0.74) 0.49 (0.32–0.74) 0.58 (0.38–0.89) 69 vs 61%, P <0.05 |
Meta-analysis found that self-monitoring or self-management were associated with a 49% reduction in major thromboembolism, a 51% reduction in all thromboembolism and a 42% reduction in death. In addition, there was a significant difference between the two groups for percentage time within therapeutic range. There was no significant benefit found for major haemorrhage. The authors state that the studies included were of variable quality and that although self-testing appears to be safer, it is unclear if this is the product of increased testing or improved patient education |
| Garcia-Alamino et al. (2010), Cochrane Database Syst Rev, United Kingdom Systematic review with meta-analysis (level 1a) |
18 RCTs n = 4723 (adults and children) |
Effect of self-monitoring or self-management vs standard management on: Thromboembolic events All-cause mortality Major bleeding Time and proportion of measurements within therapeutic range |
Pooled RR estimates: 0.50 (0.36–0.69) 0.64 (0.46–0.89) 0.87 (0.66–1.16) Not significant Data could not be pooled |
Meta-analysis found a 50% reduction in thromboembolic events, a 36% reduction in all-cause mortality but no significant improvement in major bleeding. Improvements in percentage of tests in range were reported in 17 studies, with six achieving statistical significance. However, owing to methodological differences these data could not be pooled |
| Bloomfield et al. (2011), Ann Intern Med, USA Meta-analysis (level 1a) (-) |
22 RCTs n = 8413 (adults only) |
Effect of self-monitoring or self-management vs standard management on: Thromboembolic events All-cause mortality Major bleeding Percentage of therapeutic results or percentage of time within therapeutic range |
Pooled OR estimates: 0.58 (0.45–0.75) 0.74 (0.63–0.87) 0.87 (0.75–1.05) No significant difference |
Meta-analysis found a 42% reduction in thromboembolic events and a 26% reduction in all-cause mortality. However, it was unclear if there was a beneficial effect on major bleeding. In addition, no significant difference was found between self-monitoring/self-management and standard management for either the percentage of therapeutic results, or percentage of time spent in therapeutic range. This makes it difficult to ascertain the mechanism by which thromboembolic events and mortality appear to be reduced Studies included in the meta-analysis were of variable quality and size. One study in particular represented over 25% of total patients studied |
| Heneghan et al. (2012), Lancet, United Kingdom Systematic review with meta-analysis (level 1a) |
11 RCTs n = 6417 (adults only) |
Effect of self-monitoring or self-management vs standard management on: Time to death First major haemorrhage Thromboembolism |
Pooled HR estimates: 0.82 (0.62–1.09) Not significant 0.88 (0.74–1.06) Not significant 0.51 (0.31–0.85) |
Meta-analysis demonstrated a 49% reduced risk of thromboembolism but no significant reduction in risk of death or major bleeding. Subgroup analysis not presented here found the reduction in thromboembolism greatest in those aged <55 |
RCT: randomized controlled trial; OR: odds ratio; INR: international normalized ratio; CI: confidence interval; RR: relative risk; HR: hazard ratio.