Joint Association of Low Nadir Serum Sodium and Potassium with Worse Outcomes after Ischemic Stroke

Figure 1

Youden Index plots to determine optimal cut-off points for serum (a) sodium and (b) potassium for prediction of 3-month mortality after ischemic stroke. The optimal cut point of s-sodium levels was 139.2 mmol/L with the highest YI value at 0.243, whereas the optimal cut point of the s-potassium level was 3.64 mmol/L with the highest YI value at 0.185. Based on these results, a low s-sodium level was defined as less than 140 mmol/L, whereas a low s-potassium level was defined as less than 3.65 mmol/L.