Should hemodialysis patients with atrial fibrillation undergo systemic anticoagulation? A cost-utility analysis.

BACKGROUND: Approximately 14% of hemodialysis patients have atrial fibrillation. Hemodialysis patients with atrial fibrillation appear to be at increased risk of both thromboembolic complications and bleeding. Furthermore, there is uncertainty regarding the efficacy of warfarin or acetylsalicylic acid (ASA) therapy for preventing strokes in this subgroup because they were excluded from relevant trials.

STUDY DESIGN: We performed a cost-utility analysis. Probabilistic sensitivity analysis was used to incorporate parameter uncertainty into the model. Expected value of perfect information and scenario analyses were performed to identify the important drivers of the decision and focus future research.

SETTING & POPULATION: Base case was a 60-year-old male hemodialysis patient in the United States.

MODEL, PERSPECTIVE, & TIME FRAME: A Markov Monte Carlo microsimulation model was constructed from the perspective of the health care payer, and patients were followed up during their lifetime.

INTERVENTION: We compared 3 alternative treatment strategies for permanent atrial fibrillation in hemodialysis patients: warfarin, ASA, or no treatment.

OUTCOMES: Quality-adjusted survival and cost.

RESULTS: ASA and warfarin both prolonged survival compared with no treatment (0.06 and 0.15 quality-adjusted life-years [QALYs], respectively). ASA was associated with an incremental cost-effectiveness ratio of $82,100/QALY. Warfarin provided additional benefits at a cost of $88,400 for each QALY gained relative to ASA. At a threshold of $100,000/QALY, the probabilities that no treatment, warfarin, and ASA were the most efficient therapy were 20%, 58%, and 23%, respectively.

LIMITATIONS: Parameterization data and costs were taken from US studies and may not be generalizable to other countries. Peritoneal dialysis patients were not included in the analysis.

CONCLUSIONS: The high future cost of hemodialysis constrains incremental cost-effectiveness ratios to values greater than commonly cited thresholds ($50,000/QALY). Based on available evidence, warfarin appears to be the optimal therapy to prevent thromboembolic stroke in hemodialysis patients with atrial fibrillation. Additional study is required to determine the efficacy of warfarin and risk of bleeding complications in this population so that patients can make a more informed choice.