Characteristics of included studies
| Reference . | Country . | No. of randomized patients . | Baseline INR . | Type of VKA . | VKA indication . | Treatment* . | Follow-up duration, d . |
|---|---|---|---|---|---|---|---|
| Fondevila 200122 | Argentina | 109 | Treatment, 8.4 (6.0-19.6); control, 8.1 (6.0-14.1) | A | NR | Intervention, 1 mg oral vitamin K; comparison: observation | 7 |
| Crowther 200020 | Canada | 92 | Treatment, 5.4 (4.5-9.8); control, 5.9 (4.5-9.8) | W | NR | Intervention, 1 mg oral vitamin K; comparison: placebo | 30 |
| Patel 200017 † | United States | 30 | Treatment, 7.2 (6.0-9.2); control, 7.0 (6.1-9.5) | W | VTE, 27%; AF, 44%; CVD, 7%; LVD, 13%; other, 10% | Intervention, 2.5 mg oral vitamin K; comparison: placebo | Not specified |
| Ageno 200219 | Italy, Canada | 60 | Treatment, 6.2; control, 6.0 | A | VTE, 32%; AF, 67%; stroke prophylaxis, 1% | Intervention, 1 mg oral vitamin K; comparison: observation | 30 |
| Ageno 200518 | Italy, United States | 59 | Treatment, 7.2; control, 7.7 | W | Mechanical heart value, 100% | Intervention, 1 mg oral vitamin K; comparison: observation | 30 |
| Crowther 200921 | Canada, United States, Italy | 724 | Treatment, 6.0 (4.5-9.9); control, 5.8 (4.5-9.5) | W | Thromboembolism treatment or prevention, AF, or artificial heart valve‡ | Intervention, 1.25 mg oral vitamin K; comparison: placebo | 90 |
| Reference . | Country . | No. of randomized patients . | Baseline INR . | Type of VKA . | VKA indication . | Treatment* . | Follow-up duration, d . |
|---|---|---|---|---|---|---|---|
| Fondevila 200122 | Argentina | 109 | Treatment, 8.4 (6.0-19.6); control, 8.1 (6.0-14.1) | A | NR | Intervention, 1 mg oral vitamin K; comparison: observation | 7 |
| Crowther 200020 | Canada | 92 | Treatment, 5.4 (4.5-9.8); control, 5.9 (4.5-9.8) | W | NR | Intervention, 1 mg oral vitamin K; comparison: placebo | 30 |
| Patel 200017 † | United States | 30 | Treatment, 7.2 (6.0-9.2); control, 7.0 (6.1-9.5) | W | VTE, 27%; AF, 44%; CVD, 7%; LVD, 13%; other, 10% | Intervention, 2.5 mg oral vitamin K; comparison: placebo | Not specified |
| Ageno 200219 | Italy, Canada | 60 | Treatment, 6.2; control, 6.0 | A | VTE, 32%; AF, 67%; stroke prophylaxis, 1% | Intervention, 1 mg oral vitamin K; comparison: observation | 30 |
| Ageno 200518 | Italy, United States | 59 | Treatment, 7.2; control, 7.7 | W | Mechanical heart value, 100% | Intervention, 1 mg oral vitamin K; comparison: observation | 30 |
| Crowther 200921 | Canada, United States, Italy | 724 | Treatment, 6.0 (4.5-9.9); control, 5.8 (4.5-9.5) | W | Thromboembolism treatment or prevention, AF, or artificial heart valve‡ | Intervention, 1.25 mg oral vitamin K; comparison: placebo | 90 |
A, acenocoumarol; AF, atrial fibrillation; CVD, cardiovascular disease; LVD, left ventricular dysfunction; NR, not reported; W, warfarin.
All included studies withheld vitamin K antagonist administration in the treatment and control groups.
Study fulfilled the inclusion criteria but reported 0 events and was therefore not included in the meta-analysis.
Patients may have more than 1 indication for VKA.