Evaluation of the psychometric properties of the BCPT Symptom Checklist with a sample of breast cancer patients before and after adjuvant therapy

Objective: The purpose of this analysis was to provide psychometric information related to the Breast Cancer Prevention Trial (BCPT) Symptom Checklist in women with breast cancer prior to the initiation of adjuvant therapy and 6 months post-initiation of therapy. Methods: This investigation was a secondary analysis of baseline data from the Anastrozole Use in Menopausal Women (AIM) Study (R01 CA 107408). The data used in this study were obtained from women diagnosed with Stage I, II, and IIIa breast cancer and who received adjuvant therapy that included chemotherapy alone, anastrozole alone, and chemotherapy plus anastrozole. Data were examined before adjuvant therapy (n = 278), and at 6 months post-adjuvant therapy (n = 195). Construct validity was examined through exploratory and confirmatory factor analysis (CFA), and the internal consistency of each resulting subscale was computed. Discriminant validity evidence was obtained by correlating BCPT subscales with subscales from the MOS SF-36. Results: A seven-factor structure was extracted from the 42 items at baseline; an eight-factor structure was found using 6-month data. CFA was performed to compare the baseline and 6-month models as well as an eight-factor model recommended by Cella et al. Findings revealed that the two eight-factor models best represented the data. Low negative correlations with the subscales of the MOS SF-36 provided discriminant validity evidence. Conclusion: This analysis provides evidence for the reliability, discriminant validity, and factor structure of the BCPT Symptom Checklist. Further testing of this instrument is needed to confirm the factor structure of this measure. Copyright (C) 2010 John Wiley & Sons, Ltd.