title: The number needed to be exposed: a potential use for quantifying the strength of an individual risk factor including a protective factor in a cohort study.
authors: Huai yong
authors: Hy
authors: Cheng
mesh_terms: D001943:Breast Neoplasms / Q000517:prevention & control; D015331:Cohort Studies; D005260:Female; D006801:Humans; D009043:Motor Activity; D012307:Risk Factors; D018401:Sample Size