Comparison of Accuracy of Patient and Physician Scar Length Estimates Before Mohs Micrographic Surgery for Facial Skin Cancers

IMPORTANCE: Patients are satisfied when surgical outcomes meet their expectations. Dissatisfaction with surgical scars is one of the most common reasons that patients sue surgeons who perform Mohs micrographic surgery (MMS). OBJECTIVE: To measure the accuracy of patient and physician estimations of scar length prior to skin cancer removal with MMS. DESIGN, SETTING, AND PARTICIPANTS: This cross-sectional study was conducted between December 1, 2017, and February 28, 2018, at the MMS clinic of a single tertiary referral center health system. A total of 101 adults presenting for MMS for treatment of facial skin cancers volunteered for this study, and 86 surgeons who performed the MMS procedure participated. MAIN OUTCOMES AND MEASURES: Patients and physicians independently drew the anticipated scar length on the patients’ skin prior to surgery. Preoperative estimates by patients and surgeons were compared with actual postoperative scar length. RESULTS: Of the 101 patients who participated, 57 patients (56.4%) were men and 57 patients (56.4%) were aged 65 years or older. Eighty-four patients (83.2%) underestimated scar length, whereas 67 of the 86 surgeons (77.9%) correctly estimated the scar length (P < .001). The actual postoperative scar length was 2.2 (interquartile range, 1.5-3.6) times larger than the patients’ preoperative estimate but only 1.1 (interquartile range, 1.0-1.2) times larger than the surgeons’ preoperative estimate (P < .001). Preoperative consultation with the surgeon, a personal history of MMS, or patient-directed research about MMS were not associated with improvement of patients’ estimations of scar length. CONCLUSIONS AND RELEVANCE: This study’s findings suggest that patients with facial skin cancers have unrealistic expectations regarding scars that measure, on average, less than half the length of the actual postoperative scars. Surgeons appear to accurately estimate the length of most surgical scars and have an opportunity to set realistic patient expectations about scar length before surgery.