Response to Invited Commentary Dundas et al. Respond to “Multilevel Analysis of Individual Heterogeneity”

Most research problems in epidemiology are multifaceted and, therefore, complex. The fact that they are complex should not mean that the problems cannot be researched. Sta-tistical methodology is responding to the complexity of the research challenges. In Merlo’s invited commentary (1) on our article (2), he ar-gues that although risk factor epidemiology can address some research questions, it is time to advance eco-epidemiology using appropriate statistical methods. Multiple membership multiple classification (MMMC) multilevel models have been around for some time (3) but are underused in social ep-idemiology. Multilevel models allow for individual factors (e.g., biological and lifestyle factors) and clustered groupings (e.g., neighborhoods, schools) to be studied at the same time. This enables investigation of the extent to which the differen