Correction to: Cut-off points between pain intensities of the postoperative pain using receiver operating characteristic (ROC) curves (BMC Anesthesiology, (2021), 21, 1, (29), 10.1186/s12871-021-01245-5)

Following publication of the original article [1], the authors report an error in the Method section. The formula used for determining the cut-off points from the receiver operating characteristic (ROC) curves was published incorrectly, so the authors correct the error. The formula was published as below originally. (Formula presented.).