A.1507/1755=0.859 B.79/83=0.952 C.1507/1511=0.997 D.79/327=0.242 E.1511/1838=0.822
A.79/83=0.952 B.83/1838=0.045 C.327/1838=0.178 D.248/327=0.758 E.79/327=0.242
A.人群中該病的死亡率 B.人群中該病的發(fā)病率 C.人群中該病患病率 D.暴露于某因素的頻率 E.相對危險度