In the article beginning on page 1111 in the December 2018 issue, readers are directed in Supplemental Digital Content 5 (http://links.lww. com/ALN/B779) to see the CranioScore formula and examples of the CranioScore value calculation for two simulated patients. However, both the formula and the examples table contained errors.The original formula was incorrect and incomplete. It has been corrected to specify the if/else criteria for each dichotomous variable and the units for each parameter and to include the formula for converting the CranioScore model result into the CranioScore value. The complete, corrected formula appears below.CranioScore model (CS) = -4.8094 + (1.5149 * [1 if Pre-operative Glasgow Coma Score ≤ 14, else 0]) + (1.0534 * [1 if History of brain tumour neurosurgery YES, else 0]) + (0.00878 * Greatest size of tumour, in mm) + (0.5114 * [1 if Mid-line shift ≥ 3mm, else 0) + (0.5164 * [1 if Transfusion of packed red blood cells and/or plasma and/or platelets YES, else 0]) + (0.0118 * Maximum operative Systolic Arterial Pressure, in mmHg) – (0.0130 * Minimum operative Systolic Arterial Pressure, in mmHg) + (0.2981 * Duration of surgery, in hours)CranioScorevalue %=eCS1+eCS×100In the simulated patients table, the first parameter has been corrected to read “Preoperative Glasgow Coma Score ≤ 14” rather than “Preoperative Glasgow Coma Score =15,” and the value for Simulated Patient No. 1 has been changed from “Yes” to “No” accordingly. Additionally, units have been added parenthetically for the four nondichotomous parameters. The “Duration of surgery” parameter was originally given in minutes but has been corrected to be given in hours; consequently, the value for Simulated Patient No. 1 has been corrected from 110 to 1.8, and that for Simulated Patient No. 2 from 118 to 2.0. Last, the final CranioScore value (%) for Simulated Patient No. 2 has been corrected from 8.9 to 31.0%. The corrected table appears below.The authors regret these errors. The online version of the Supplemental Digital Content has been corrected and replaced.