Development and Psychometric Validation of the BREAST-Q Animation Deformity Scale for Women Undergoing an Implant-Based Breast Reconstruction After Mastectomy
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BACKGROUND: To assess the impact of animation deformity on health-related quality of life, a content-specific, valid, and reliable patient-reported outcome measure is needed. This report describes the development and validation of the BREAST-Q Animation Deformity scale. METHODS: Women with breast cancer who had an implant-based reconstruction provided data. In phase 1 (January 2017 and December 2018), qualitive and cognitive patient interviews and expert input were used to develop and refine scale content. In phase 2 (March to June 2019), a field test study with members of the Love Research Army (LRA) was conducted. Rasch Measurement Theory (RMT) analysis was used to examine psychometric properties. RESULTS: In phase 1 of the study, qualitative (n = 11) and cognitive (n = 4) interview data and expert input (n = 9) led to the development of a 12-item scale measuring animation deformity. In phase 2, 651 LRA members provided data and 349 participated in a test-retest study. In the RMT analysis, the data fit the Rasch model (X2(96) = 104.06; p = 0.27). The scale's reliability was high, with person separation index and Cronbach alpha values with/without extremes of ≥ 0.84 and ≥ 0.92 respectively, and an intraclass correlation coefficient of 0.92 (95% confidence interval, 0.90-0.94). Mean scores on the Animation Deformity scale varied as predicted across subgroups of participants who reported differing amounts of change in breast appearance when their arms were lifted overhead or when they lifted something heavy, and for increasing happiness with the overall outcome of their breast reconstruction. CONCLUSION: The 12-item Animation Deformity scale forms a new scale in the BREAST-Q Reconstruction Module that can be used in comparative effectiveness research or to inform clinical care.