Credibility of a Meta-Analysis: Evidence-Based Practice Concerning Soy Intake and Breast Cancer Risk in Premenopausal Women

Purpose: To report the findings from a critical appraisal concerning the credibility of a meta-analysis (M-A) about the role of dietary soy intake in reducing breast cancer risk. The use of an evidence-based, advanced nursing practice framework was used to appraise the M-A. Approach: The clinical question was developed from a problem that could be encountered in clinical practice. For premenopausal women, does the use of high dietary soy intake reduce the future risk of breast cancer compared with low dietary soy intake ? A search of electronic databases yielded one M-A, which was selected to answer the question. Framework: A framework was developed from various authors' work and used to appraise the M-A and guide implementation of the evidence-based practice (EBP) process. Conclusions: The findings of the M-A were not deemed credible because of deficient information regarding the target population and outcome variable, lack of confounder control, unclear inclusion and exclusion criteria of the sample, and invalid methods of data abstraction. Because the findings were not credible, they were deemed not to be clinically applicable. Therefore, a high soy diet would not necessarily be recommended.