The Think Tank participants discussed advantages and opportunities for conducting new studies using innovative designs. The focus of this paper has been on case-control or nested case-control study designs. Family-based designs may provide some advantages over case-control studies due to robustness to population stratification, ability to make genetic inferences by comparisons to family members, increased power for assessing GxE interactions [Witte, et al. 1999], and resistance to self-selection of controls [Shi, et al. 2011; Weinberg 2012a]. Extensions to these methods have been developed that complement some of the case-control methods described in this paper [Chatterjee, et al. 2005; Kistner, et al. 2009]. However, population stratification remains an issue in family studies of GxE interactions. Several alternatives such as the tetrad design or sibling augmented case-only (SACO) are being explored to address those robustness issues [Shi, et al. 2011; Weinberg, et al. 2011], and work in this area is merited to facilitate the use of data collected under these family study designs.
