OBJECTIVES: Atrial Fibrillation (AF) has been a major risk factor for the development of stroke making anticoagulation therapy necessary. While on prophylaxis treatment, renal impaired patients on conventional anticoagulation (Warfarin) are at an increased risk for major bleeding. Apixaban has been shown to have better safety profile than Warfarin in face to face clinical trial. However, no study were found to have compared the cost effectiveness of Apixaban with Warfarin among renal impaired patients. We attempted to estimate the short term (one year) cost effectiveness of Apixaban compared to Warfarin for stroke prophylaxis among renal impaired patients. METHODS: We developed a decision analytic model to compare Apixaban 2.5mg/5.0 mg twice daily with dose adjusted Warfarin (INR: 2.0-3.0). Cost effectiveness was calculated separately among the patients with Severe to Moderate (25<CrCl≤50 ml/min) and Mild (50<CrCl≤80 ml/min) renal impairment. Only primary efficacy (event rate of stroke) and safety (event rate of major bleeding) were taken into consideration. Probabilities, effectiveness and safety were calculated using the clinical data from ARISTOTLE trial (NCT00412984). Inputs for cost were sourced from published US based studies. RESULTS: One year cost for Apixaban and warfarin was calculated as $3,670 and $2,075 respectively. Incremental cost to avert an additional event of stroke and major bleeding using Apixaban were $290,926 and $63,245 among patients with severe to moderate and $412,665 and $330,132 for mild renal function respectively as compared with warfarin. Among various sensitivity analyses, cost of Apixaban was found to have highest impact. CONCLUSIONS: This decision analysis suggested that anticoagulation with Apixaban is a cost effective therapy as compared to dose adjusted warfarin for stroke prophylaxis among renal impaired patients. This study also indicated that severe to moderate renal impaired patients benefitted more with Apixaban compared to Warfarin.