Treatment effects of rivaroxaban vs warfarin in patients receiving no AAD were consistent with results from the overall trial ( primary end point : adjusted HR 0.82 ; 95 % CI 0.68-0 .98 ; Pinteraction = .06 ; safety end point : adjusted HR 1.12 ; 95 % CI 0.90-1 .24 ; Pinteraction = .33 ) .