Variables | Value | Low CI | High CI | Distribution | Ref |
Probability of NSR at 1 year | |||||
RFCA | 0.8405 | 0.5579 | 0.9631 | Posterior | |
AADs | 0.3682 | 0.1060 | 0.7083 | Posterior | |
Odds ratio | 0.0968 | 0.0520 | 0.1641 | Posterior | |
Annual probability of recurrent AF after year 1 | |||||
RFCA | 0.0335 | 0.0220 | 0.0451 | Beta | 10 |
AADs | 0.2883 | 0.2323 | 0.3456 | Beta | 11 |
Stroke risk for AF (%) | |||||
CHADS2 = 0 | 1.9 | 1.2 | 3.0 | Beta | 12 |
CHADS2 = 1 | 2.8 | 2.0 | 3.8 | Beta | 12 |
CHADS2 = 2 | 4.0 | 3.1 | 5.1 | Beta | 12 |
CHADS2 = 3 | 5.9 | 4.6 | 7.3 | Beta | 12 |
Hazard ratio relative to NSR* | 1.60 | 1.11 | 2.30 | Log normal | 14 |
Stroke risk reduction with OACs (RR) | |||||
Warfarin relative to placebo | 0.33 | 0.24 | 0.45 | Log normal | 13 |
Warfarin relative to aspirin | 0.59 | 0.40 | 0.86 | Log normal | 13 |
OAC use (%) | |||||
Warfarin | 64.0 | – | – | Dirichlet | 15 |
Aspirin | 27.3 | – | – | Dirichlet | 15 |
None | 8.7 | – | – | Dirichlet | 15 |
Mortality risk from stroke (RR) | |||||
In year 1 | 7.40 | 6.50 | 8.50 | Betapert | 16 |
In subsequent years | 2.30 | 2.00 | 2.70 | Betapert | 16 |
Adverse toxicity from AADs (%) | |||||
General toxicity (year 1) | 12.50 | 10.00 | 15.00 | Betapert | 22 |
General toxicity (⩾ 2 years) | 6.25 | 5.00 | 7.50 | Betapert | 22 |
Withdrawal due to toxicity (year 1) | 10.00 | 6.25 | 12.50 | Betapert | 22 |
Withdrawal due to toxicity (⩾ 2 years) | 5.00 | 3.13 | 6.25 | Betapert | 22 |
Pulmonary complication given withdrawal | 15.19 | 1.00 | 30.00 | Betapert | 22 |
Irreversible pulmonary complication | 25.00 | 0.00 | 30.00 | Betapert | 22 |
Mortality from irreversible pulmonary event | 20.00 | 5.00 | 25.00 | Betapert | 22 |
Adverse bleeding from OACs (%) | |||||
Major bleed on warfarin | 2.40 | 1.70 | 8.10 | Betapert | 26 |
Minor bleed on warfarin | 15.80 | 15.00 | 16.60 | Betapert | 26 |
Bleeding risk reduction on aspirin (RR) | |||||
Major bleed | 0.58 | 0.35 | 0.97 | Log normal | 13 |
Minor bleed | 0.45 | 0.32 | 0.64 | Log normal | 13 |
Bleeding risk reduction on no OACs (RR) | |||||
Major bleed | 0.45 | 0.25 | 0.82 | Log normal | 13 |
Minor bleed | 0.46 | 0.36 | 0.59 | Log normal | 13 |
RFCA procedural complications (%) | |||||
Operative death | 0.05 | 0.00 | 0.09 | Beta | 9 |
Cardiac tamponade | 1.22 | 0.99 | 1.45 | Beta | 9 |
Stroke | 0.28 | 0.16 | 0.40 | Beta | 9 |
PV stenosis | 0.74 | 0.54 | 0.94 | Beta | 9 |
Mean number of procedures per patient | 1.304 | 1.293 | 1.315 | Normal | 9 |
Utilities associated with health states | SE | ||||
Decrement for NSR given RFCA | 0.0000 | – | 30 | – | 27 |
Decrement for NSR given AADs | 0.0199 | 0.0100 | – | Gamma | 27 |
Decrement for AF given RFCA | 0.0034 | 0.0017 | – | Gamma | 28 |
Decrement for AF given AADs | 0.0925 | 0.0361 | – | Gamma | 28 |
Disabled stroke | 0.38 | 0.0460 | – | Beta | 19 |
Non-disabled stroke | 0.74 | 0.0260 | – | Beta | 19 |
Combined stoke (30.9% disabled) | 0.63 | – | – | – | 19 |
Decrement for pulmonary toxicity | 0.0329 | 0.0030 | – | Gamma | 21 |
Decrement for non-pulmonary toxicity or bleeding event (days of perfect health lost) | 1 | 0 | – | Betapert | 22 |
Unit costs (£) | |||||
RFCA accumulated cost† | 9810 | – | – | Fixed | |
Complication from cardiac tamponade | 815 | – | – | Fixed | 18 |
Complication from PV stenosis | 3217 | – | – | Fixed | 18 |
Outpatient initiation of amiodarone | 154 | – | – | Fixed | 18 |
Amiodarone (200 mg daily, per annum) | 32 | – | – | Fixed | 29 |
AF health state (per annum) | 646 | – | – | Fixed | 2 |
NSR health state (per annum) | 646 | – | – | Fixed | 2 |
Stroke (year 1) | 9431 | – | – | Fixed | 19 |
Stroke (⩾ 2 years, per annum) | 2488 | – | – | Fixed | 19 |
Warfarin (5 mg daily, per annum) | 19 | – | – | Fixed | 29 |
Aspirin (75 mg daily, per annum) | 20 | – | – | Fixed | 29 |
Toxic event | 1497 | – | – | Fixed | 30 |
Reversible toxicity (per day) | 0.43 | – | – | Fixed | 29 |
Irreversible toxicity (50 mg daily) | 158 | – | – | Fixed | 29 |
Major bleeding event | 1573 | – | – | Fixed | 26 |
Minor bleeding event | 87 | – | – | Fixed | 26 |
AAD, anti-arrhythmic drug; AF, atrial fibrillation; CHADS2, congestive heart failure, hypertension, age 75, diabetes mellitus, and prior stroke; CI, confidence interval or credible interval; NSR, normal sinus rhythm; OAC, oral anticoagulants; PV, pulmonary vein; RFCA, radiofrequency catheter ablation; RR, relative risk; SE, standard error.
*Used to determine the stroke risk for NSR. The hazard ratio is applied to the CHADS2 stroke risk scores for AF.
†RFCA procedural cost consists of total consumable (£5687), ward (£182 based on 2 days), and lab (£1979 based on 200 minutes) costs plus VAT and administration costs (Fitzpatrick A, personal communication, 2007).