The method offers promise as a way to structure analysis of combined effects for stressor-based evaluations.
The whole-genome DNA microarray data provide a resource for the analysis of combined effects of age, diet, and sex on gene expression in the gonads.
From this analysis, the combined effects of the two drugs can be summarized as follows: CI = 1 indicates summation (additive and zero interaction); CI < 1 indicates synergism; and CI > 1 indicates antagonism.
Firstly, the heterogeneity of the study designs prohibited meta-analysis, so study findings were not weighted, and there were no analysis of the combined effect or sensitivity analysis for the effect of multiple confounders identified, including the risk of bias of included studies.
The effect estimates extracted from the individual studies are given in the Supplemental Material, Table 1 (doi:10.1289/ehp.0900844) and are illustrated in Figures 1– 3, which also give the combined effects calculated in the meta-analysis.
In addition, we also examined the combined effect of both sensitivity analysis assumptions.
Objectives: We aimed to investigate the association between air pollution and pneumonia, croup, and otitis media in 10 European birth cohorts BAMSE (Sweden), GASPII (Italy), GINIplus and LISAplus (Germany), MAAS (United Kingdom), PIAMA (the Netherlands), and four INMA cohorts (Spain)—and to derive combined effect estimates using meta-analysis.
For the meta-analysis, data on total T, free T and SHBG were extracted and combined using random effects analysis.
We conducted gene expression meta-analysis by combining effect sizes (standardized mean differences) as previously described in detail [ 20].
Traditional meta-analysis techniques combine effect sizes across studies requiring a research question to have been previously assessed.
