Identifying intraclass correlations necessitating hierarchical modeling

Hierarchical binary outcome data with three levels, such as disease remission for patients nested within physicians, nested within clinics are frequently encountered in practice. One important aspect in such data is the correlation that occurs at each level of the data. In parametric modeling, accounting for these correlations increases the complexity. These models may also yield results that lead to the same conclusions as simpler models. We developed a measure of intraclass correlation at each stage of a three-level nested structure and identified guidelines for determining when the dependencies in hierarchical models need to be taken into account. These guidelines are supported by simulations of hierarchical data sets, as well as the analysis of AIDS knowledge in Bangladesh from the 2011 Demographic Health Survey. We also provide a simple rule of thumb to assist researchers faced with the challenge of choosing an appropriately complex model when analyzing hierarchical binary data.     

Parenting in 2 Worlds: Testing improved parent–adolescent communication about sexuality in Urban American Indian families

Urban American Indian (AI) adolescents are more likely than non-Natives to have early sexual debut, teen pregnancies, sexually transmitted infections, and inadequate sexual health information. A RCT in three Arizona cities, with 585 parents of urban AI adolescents, tested whether a culturally tailored parenting intervention for urban AI families, Parenting in 2 Worlds (P2W), increased parent–adolescent communication about sexuality, compared to an informational family health intervention that was not culturally tailored. P2W produced significantly larger increases on two measures: communication about general sexual health and about sexual decision-making. The desired effects of P2W on the first measure were stronger short-term for cross-gender dyads, while for the second measure, they were stronger long-term for both mothers and fathers of adolescent sons.