Affiliate stigma scale: a reliable and valid stigma measure for caregivers of women with breast cancer

Introduction: Apart from the fact that breast cancer patients experience self-blame and stigmatisation, their families may also face discrimination and societal rejection due to prevailing myths, misconceptions and causal beliefs related to breast cancer. Although a scale has been introduced to measure affiliate stigma in caregivers of cancer patients, it has not yet been psychometrically tested. This study aims to develop and validate a measurement tool that is sensitive to the affiliate stigma experienced by caregivers of women with breast cancer. Methods: The scale was developed in two phases: (a) item generation based on interviews amongst 18 caregivers of women with breast cancer; (b) psychometric properties of the scale, including content validity, structural validity, and internal consistency reliability. Data were collected from May to June 2023 in 426 caregivers of women with breast cancer from 5 tertiary A hospitals. Findings: An exploratory factor analysis produced a 24-item scale across four dimensions. The scale also showed good internal consistency and test–retest reliabilities. The total score of the scale was significantly and positively correlated with scores in caregiving burden and negatively correlated with scores in self-esteem and in social support. The item-level content validity index fell within the range of 0.8–1.0. Interpretation: The is a valid and reliable instrument to assess affiliate stigma status amongst caregivers of women with breast cancer and may serve as a unique instrument that can be used globally. The scale captured the spectrum of stigma relevant to caregivers of women with breast cancer.