Detecting optimal cut-off value of international normalized ration by receiver operator characteristic curve in diagnosis of hemorrhage in patients with nonvalvular atrial fibrillation receiving wafarin / 中华老年医学杂志

ABSTRACT

Objective To evaluate the value of international normalized ratio (INR) in predicting and diagnosing hemorrhagic events in patients with nonvalvular atrial fibrillation (NVAF)receiving wafarin, to determine the optimal cut-off value of INR for predicting hemorrhagic events by receiver operator characteristic (ROC) curve. Methods The data of 231 patients with NVAF receiving wafarin were retrospectively analyzed, including 93 patients with hemorrhagic events and 138cases without hemorrhagic events as control group. The PT and INR were detected by Sysmex CA-500 with Medcalc software plotting ROC curve. Results The area under the ROC curve for INR was 0. 822 (95%CI 0. 717-0. 900), the analysis of ROC curve revealed the optimal cut-off value of INR was 2.71, which presented a sensitivity of 77.40% and a specificity of 78.30%. Conclusions Through evaluation by ROC curve, the new cut-off value provides substantial improvement in sensitivity, with an acceptable loss of specificity. The value on predicting hemorrhagic events is better, the discriminative power of INR between hemorrhagic events and nonhemorrhagic events is satisfactory. The cut-off value of INR can guide the clinical physicians to predict the risks of hemorrhagic and promote proper use of clinical medications.