Meta-analysis and its problems.
Including all relevant material--good, bad, and indifferent--in meta-analysis admits the subjective judgments that meta-analysis was designed to avoid. Several problems arise in meta-analysis: regressions are often non-linear; effects are often multivariate rather than univariate; coverage can be restricted; bad studies may be included; the data summarised may not be homogeneous; grouping different causal factors may lead to meaningless estimates of effects; and the theory-directed approach may obscure discrepancies. Meta-analysis may not be the one best method for studying the diversity of fields for which it has been used.
Eysenck
H J
HJ
Institute of Psychiatry, London.
D003625:Data Collection; D006801:Humans; D015201:Meta-Analysis as Topic; D015999:Multivariate Analysis; D012044:Regression Analysis; D015983:Selection Bias; D012680:Sensitivity and Specificity