Linguistic and Psychometric Validity of the Malay BREAST-Q in Women Undergoing Breast Cancer Surgery in Malaysia
Authors: Shunnmugam B. , Sinnadurai S. , Chua S.H. , Islam T. , See M.H. , Chinna K. , Taib N.A. Mohd 
Published: September 2018

Background: BREAST-Q is a PROMs used to measure and assess patient satisfaction and quality of life before and after breast cancer surgery. BREAST-Q composed of 5 different modules and each module comprised of multiple scales. Each module has preoperative and postoperative versions to assess the impact of surgery. Four subscales with common items from the 5 modules: “satisfaction with the breast”, psychosocial, sexual and physical well-being were subjected to testing. Two other subscales, “satisfaction with overall outcomes” and “satisfaction with the care” were only validated linguistically. Currently, the BREAST-Q has already been translated into 25 languages. Linguistic and psychometric validation of BREAST-Q has not been performed in Malaysia. Aim: To translate the BREAST-Q into Malay language and perform psychometric validation. Methods: Translation of the English BREAST-Q to Malay language was done based on linguistic validation protocol provided by MAPI Research Trust. Content and face validation were performed to determine contextual accuracy, acceptability and understanding of the items. The finalised Malay BREAST-Q then underwent psychometric testing. Breast cancer patients (n=186) who were planned for breast cancer surgery were conveniently sampled at the breast clinic of UMMC between June 2015 to June 2016. Consented participants completed the questionnaire in the same visit following their diagnosis. Retest was done 2-3 weeks after the first questionnaire administration in 62 patients who were admitted for their surgery. Data were analyzed using SPSS and AMOS software. Results: Content experts (4 breast surgeons) agreed the items in BREAST-Q comprehensively measured the concept of interest and I-CVI for each item was 1.0. Participants agreed the questionnaire was comprehensive and easy to understand. The average time taken to complete the questionnaire was 15.3 minutes. Test–retest analysis showed good reproducibility with intraclass correlation coefficient (ICC) value of 0.71-0.98. Internal consistencies were good for all items in each subscale with Cronbach's alpha values of 0.83-0.95. The highest interitem correlation for each item with at least one other item in the construct ranged from 0.47 to 0.90. The lowest corrected item-total correlation (CITC) values ranged from 0.47 to 0.72. In exploratory factor analysis, the KMO values were excellent in all 4 subscales (0.76, 0.92, 0.91, and 0.86). Single factor was extracted in 3 subscales that explained more than 50% of the variance and 3 factors (breast pain, general pain, and discomfort) were extracted in “physical well-being” subscale that cumulatively explained more than 50% of the variance. Conclusion: The Malay BREAST-Q demonstrated good reliability, content and face validity, and excellent psychometric properties. Hence, we propose the use of the Malay BREAST-Q to measure patient reported outcomes among breast cancer patients in Malaysia undergoing breast cancer surgery.