studying the factor analysis and psychometric properties of the functional assessment of cancer therapy - breast (fact-b) scale version 4 in women with breast cancer.

objective: functional assessment of cancer therapy - breast (fact-b) scale, is widely used to measure health-related quality of life in cancer patients. the aim of the present study was to validate the fact-b in a sample of iranian women with breast cancer.   method: the sample consisted of 300 women with breast cancer that selected through non-random convenient sampling procedure from oncology hospitals and clinics in kermanshah and shiraz cities. they were asked to persian version of fact-b scale, hospital anxiety and depression scale questionnaire, the european organization for research and treatment of cancer quality of life eortc qlq30.confirmatory  factorial analysis of the methods, concurrent validity and  discriminative, and cronbach's alpha for internal consistency of was used.   results: internal consistency using cronbach's alpha from 0.63 to 0.93 for the subscales and 0/92 total scale. significant correlations between fact- b and other measures also indicate that this scale has concurrent validity and discriminative. the values ​​of fit indices were also moderate.   conclusion: the persian version of the fact-b scale is valid and reliable and, therefore, the scale can be used in research and clinical settings to assess health-related quality of life in iranian patients with breast cancer to be used.