Measuring Outcomes Relevant to the Decolletage from the Patient Perspective: Development and Validation of the BODY-Q Decolletage Scale

Abstract Background A range of cosmetic treatments to improve skin quality of the decolletage are available. To measure outcomes from the patient perspective, a rigorously developed patient-reported outcome measure is needed. Objectives To develop and validate the BODY-Q Decolletage scale. Methods Appearance-related codes from BODY-Q concept elicitation interviews were reexamined and 13 items drafted and refined through patients and clinician debriefing interviews. The scale was tested in an online international sample of women >25 years who had previously received a treatment for the decolletage, or in the past 12 months had received a cosmetic treatment at a plastic surgery or dermatology clinic. Data were analysed with both Rasch measurement theory and classical test theory. Results Interviews conducted with 15 patients and 5 clinicians led to a 16-item scale with items that covered scenarios (mirror, photos, low neckline, lay on side, breasts together, arms crossed, get up, up close), compared (other people), age (youthful, age), qualitative (attractive, healthy), color (even-colored) and texture (smooth, texture). The field-test included 334 participants. An item with poor fit to the Rasch model was dropped. Data for the remaining 15 items fit the Rasch model (Chi-square=76.72, df=60, p=0.07). All items had ordered thresholds and good item fit. All reliability statistics were >0.93. A total of 19 of 20 pre-defined hypotheses (95%) were met providing evidence of construct validity. Conclusions The Decolletage scale is available to incorporate the perspective of patients into clinical care and clinical trials of minimally invasive treatments to improve skin quality.