·       Environmental factors (e.g., high workload, fatigue, change of personnel)

·       Exclusion of surgical team members, patient and their family members in pre-operative assessment

·       Extenuating patient characteristics (e.g., physical or mental incapacitations or disabilities, language barrier, morbid obesity)

·       Illegible handwriting

·       Inadequate medical record review

·       Inadequate patient assessment

·       Incomplete or inaccurate communication among surgical team members, or between surgical team member and patient

·       Involvement of more than one surgeon in procedure

·       Lack of institutional policies and controls

·       Mislabeled or misinterpreted laterality markings on radiographs, computed tomogram and magnetic resonance images

·       Performance of multiple procedures on multiple parts of a patient at one time

·       Presence of multiple prior treatment or biopsy sites

·       Pressure to reduce pre-operative preparation time

·       Reliance solely on the surgeon to determine correct surgical site

·       Similar patient names

·       Similar procedures performed back to back in same room

·       Unusual operating room setup or equipment (e.g., change of patient’s position during procedure, rotation of surgical table)

·       Unusual time pressures or emergencies

·       Use of abbreviations related to surgical procedure, site, laterality

·       Wrong side draped or prepped