Development and evaluation of a psychosocial adaptation questionnaire for women with breast cancer treated with adjuvant endocrine therapy: a single-centre, cross-sectional study in China

OBJECTIVE: To develop and evaluate a psychosocial adaptation (PSA) questionnaire of women with breast cancer treated with adjuvant endocrine therapy (AET). DESIGN: Cross-sectional study. SETTING: Conducted study in a tertiary care centre in China from March to June 2021. PARTICIPANTS: Women with breast cancer who have received AET. METHODS: Item development and extraction were based on literature, qualitative interviews (n=16) and assessment of content validity. 300 participants were recruited to perform item analysis, internal consistency reliability and exploratory factor analysis by cross-sectional studies. Finally, test–retest, criterion validity and confirmatory factor analysis of the questionnaire were performed with 96 respondents. RESULTS: An initial questionnaire was devised. The exploratory factor analysis demonstrated four factors: emotional response (six items), self-worth (five items), physical impacts (three items) and social communication (two items). The cumulative contribution of the factors was 65.057%. Cronbach’s alpha coefficient of the questionnaire was 0.876. The correlation coefficient between the questionnaire and General Self-Efficacy Scale was 0.565 (p<0.01). A 16-item questionnaire and its factorial structure were confirmed. CONCLUSIONS: The 16-item questionnaire had good reliability and validity. This could be a useful tool to assess the PSA levels among women with breast cancer treated with AET and provide a basis for further research.