Table 2.
Annual stroke risk and severity by CHADS2 risk score, AF status and anticoagulant treatment received
| CHADS2 score | No AF | AF | ||||
| No treatment | Aspirin | No treatment | Aspirin | NOAC*† | Warfarin* | |
| 0 | 0.2% | 0.2% | 1.1% | 0.8% | 0.3% | 0.3% |
| 1 | 0.6% | 0.5% | 3.1% | 2.2% | 0.8% | 0.8% |
| 2 | 1.3% | 0.9% | 6.3% | 4.5% | 1.7% | 1.7% |
| 3 | 2.5% | 1.8% | 12.0% | 8.6% | 3.3% | 3.2% |
| 4 | 3.2% | 2.3% | 15.3% | 10.9% | 4.2% | 4.1% |
| 5 | 3.6% | 2.6% | 17.2% | 12.3% | 4.7% | 4.6% |
| 6 | 4.0% | 2.9% | 19.2% | 13.7% | 5.3% | 5.1% |
| IS severity | Mild: 42%; moderate: 26%; severe: 10%; fatal: 22% | |||||
*NOAC was used as treatment in base-case analysis and warfarin was considered in sensitivity analysis.
†A class-effect for NOAC was assumed by taking the average efficacy of apixaban, dabigatran (low and high dose), rivaroxaban, edoxaban (low and high dose).11
‡IS risk was adjusted by a factor of 1.46 (95% CI 0.8 to 2.16) per decade.13
AF, atrial fibrillation;IS, ischaemic stroke;NOAC, new oral anticoagulant.