The Patient Scar Assessment Questionnaire: A Reliable and Valid Patient-Reported Outcomes Measure for Linear Scars

Abstract

There is a lack of rigorously validated patient-based outcomes measures of scarring. The aim of this study was to construct such a scale and demonstrate reliability and validity by applying the scale in a wide range of scarring samples. The Patient Scar Assessment Questionnaire with five subscales (i.e., Appearance, Symptoms, Consciousness, Satisfaction with Appearance, and Satisfaction with Symptoms) was constructed using multiple categorical response items. The Patient Scar Assessment Questionnaire was applied to various surgical samples (total scar assessments n = 667) at months 3, 6, and 12 after surgery (and preoperatively in the scar revision group) and tested for internal consistency, test-retest reliability, convergent validity, known group differences, and sensitivity, against widely accepted criteria from psychometric measurement science. Subscales showed high internal consistency (Cronbach alpha, 0.73 to 0.93), except the Symptoms subscale. Test-retest reliability was high across all subscales (intraclass correlation coefficient, 0.74 to 0.87) across all groups except the scar revision group. Change in Patient Scar Assessment Questionnaire scores was significant between months 3 and 6 postoperatively (p < 0.001) and subscales demonstrated known group differences (p < 0.001). Convergent validity was demonstrated by significant moderate correlations with various measures of similar constructs (r = 0.26 to 0.61, p < 0.001). The Patient Scar Assessment Questionnaire is a reliable and valid measure of the patient's perception of scarring, although the Symptoms subscale requires further refinement. Subscales can be used independently of each other to allow assessment of scar change in specific domains.