Evaluation of effect of frailty on warfarin compliance among older patients

Abstract

Aim: Warfarin has a narrow therapeutic index. We aimed to evaluate the effect of frailty on compliance to warfarinpharmacotherapy and the attainment of international normalized ratio (INR) goals in patients aged over 65 years receivingwarfarin.Material and Method: We recruited 473 elderly subjects aged 65 years and over. Indications for the administration of warfarinand INR values were recorded. All patients were assessed according to the Clinical Frailty Scale of the Canadian Health andAging Study. Whether or not the target of INR values and the degree of frailty were compared.Results: Of the 473 patients, 401 patients were assigned to the non-frail group and 72 patients were assigned to the frail group.When patients were compared according to the attainment of target INR values, a negative correlation between frailty andnumerical INR values was observed.Conclusion: It can be said that the presence of frailty negatively affects reaching the target INR values in patients over 65 yearsof age using warfarin. If patients in this population are indicated for warfarin use, it is necessary to be sure that INR monitoring will be done well.