Chunk #45 — 6. The wider picture of replication efforts: consortia, data availability, and field synopses — 6.ii. Anthropometrics and the analysis of “secondary traits”
the strength of the association between the secondary trait and disease (which could be modest or controversial, as in the case of smoking and breast or prostate cancer, or quite strong, as in the case of BMI and T2D or smoking and lung cancer) and the strength of the association between the marker and disease (typically relatively weak). [75, 76] Moreover, the risk of false positives may be further ameliorated by diversity of designs among the participating studies some may have originally been case-control studies of different diseases, others may have been cohort or cross-sectional studies. Although there are analytic methods that can eliminate spurious association or bias due to case-control ascertainment in particular situations and under particular assumptions, [74, 76] these should not replace careful consideration of potential biases and evaluation of heterogeneity in effect measures across studies with different designs.
