Re: [申覆] 醫學一 (98)

看板medstudent (醫學生)作者stberry (鮮紅)時間14年前 (2011/08/02 20:28)推噓0(0推 0噓 1→)

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※ 引述《ri1966 (YM)》之銘言： : 98 . : 下列有關個案對照研究（case-control study）「配對（matching）」的敘述，何者錯誤？ : (A)在個案對照法可增加效率 : (B)以密度取樣法是以時間配對取對照組 : (C)配對可增加各受測者資料量 : (D)配對之目的在增加研究設計之效度 : 答案: D : 建議答案: C 或 D : 我記得配對無法增加資料量跟公衛的同學確認了一下似乎是這樣沒錯 : 可是我手頭沒課本可以佐證... : 而且我晚上就要出國一周了Orz : 有人可以幫忙一下這題嗎? 引用自Epidemiology 4th ed, Leon Gordis Conceptual Problems with Matching: Perhaps a more important problem is the conceptual one: Once we have matched controls to cases according to a given characteristic, we cannot study that characteristic. For example, suppose we are interested in studying marital status as a risk factor for breast cancer. If we match the cases (breast cancer) and the controls (no breast cancer) for marital status, we can no longer study whether or not marital status is a risk factor for breast cancer. Why not? Because in matching according to marital status we have artificially established an identical proportion in cases and controls: if 35% of the cases are married, and through matching we create a control group in which 35% are also married, we have artificially ensured that the proportion of married subjects will be identical in both groups. By using matching to impose comparability for a certain factor, we ensure the same prevalence of that factor in the cases and the controls. Clearly, we will not be able to ask whether cases differ from controls in the prevalence of that factor. We would therefore not want to match on the variable of marital status in this study. Indeed, we do not want to match on any variable that we may wish to explore in our study. 以黃色字來看，受測者資料量應該會變少才是（被配對的條件不能使用）至少也不應該變多才對不曉得直接引用這段的公信力夠不夠？請大家給點意見謝謝（另外如果只有電子書的話，寫不出頁數，可以直接把章節段落貼上去嗎？） -- ※ 發信站: 批踢踢實業坊(ptt.cc) ◆ From: 140.112.24.90