Comment: The quality of evidence is downgraded by study quality (unclear allocation concealment).
A Cochrane review included 28 studies with a total of 8 950 subjects. Patients who self-test can either adjust their medication dose according to a pre-determined dose-INR schedule (self-management) or they can call a clinic to be told the appropriate dose adjustment (self-monitoring). Compared to standard therapy, self-monitoring or self-management of oral anticoagulation led to a significant 50% reduction in thromboembolism but no reduction in all-cause mortality. However, trials of self-management led to a significant reduction in all-cause mortality. In those groups that self-managed the effect for thromboembolic events was larger than in the groups that self-monitored (table ) Self-monitoring or self-management did not reduce major haemorrhage (RR 0.95, 95% CI, 0.80 to 1.12; 20 studies, n=8018) or minor haemorrhage (RR 0.97, 95% CI 0.67 to 1.41; 13 studies, n=5 365).
| Outcome and intervention | RR (95% CI) | Assumed risk - standard care | Corresponding risk - intervention (95% CI) | Participants (studies) |
|---|---|---|---|---|
| Thromboembolic events | ||||
| Self-monitoring or self-management | RR 0.58 (0.45 to 0.74) | 35 per 1000 | 21 per 1000 (16 to 26) | 7 594 (18 studies) |
| Self-monitoring | RR 0.69 (0.49 to 0.97) | 35 per 1000 | 24 per 1000 (17 to 34) | 4 097 (7 studies) |
| Self-management | RR 0.47 (0.31 to 0.70) | 36 per 1000 | 17 per 1000 (12 to 25) | 3 497 (11 studies) |
| All-cause mortality | ||||
| Self-monitoring or self-management | RR 0.85 (0.71 to 1.01) | 64 per 1000 | 54 per 1000 (45 to 64) | 6 358 (11 studies) |
| Self-monitoring | RR 0.94 (0.78 to 1.15) | 90 per 1000 | 85 per 1000 (70 to 104) | 3 300 (3 studies) |
| Self-management | RR 0.55 (0.36 to 0.84) | 33 per 1000 | 18 per 1000 (12 to 28) | 3 058 (8 studies) |
Self-monitoring and self-management are not feasible for all patients, which requires the identification and education of suitable patients.