what wrong? Positive result from either observational or case-control
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送交者: blackbox 于 2007-01-03, 13:07:27:
回答: wrong concept 由 xj 于 2007-01-03, 12:46:29:
can not give casual relationship, I knew that, but many guidelines or policies are based on studies with regardless of study type, although some may provide grading information about the studies.
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