Which of the following is correct about meta-analysis?

A.Individual data need to be obtained in order to perform
meta-analysis B.Studies with missing data should be excluded C.The weight of each study should depend on the effect size D.The weight of each study should depend on the sample size E.Trial quality factor should be incorporated into the meta-analysis

[正确答案]： D

The sample size is normally taken into account for weighting of
each study in a meta-analysis. Therefore, the weight of each study
should depend on the sample size.

Meta-analysis can be performed on aggregate data, provided that
sufficient information is available.

It is not mandatory to exclude studies with missing data.

The effect size should not affect the weight of each study,
although it will affect the final result.

Trial quality is usually not incorporated into meta-analysis
nowadays since the weightings can be subjective and arbitrary.