Statistical analysis
REGRESSION
To examine this hypothesis, we exploit our study design which has a multifactorial design embedded in a cluster randomized controlled trial. Multifactorial experimental designs combine the rigor of experimental design with the ability to produce results on the effectiveness of alternate approaches to multicomponent interventions in a single experiment. We will use multilevel regression analysis and test for an interaction effect between the environmental and individual level interventions (E+I). The presence of a significant interaction between E and I on the primary outcome of physical activity suggests synergy between these components of the intervention. If the effects of the environmental level intervention and individual level intervention are additive there should not be a significant interaction in the model. In this case, we can compare the interaction results to the multilevel intervention group (E+I) to examine the exploratory hypothesis that E+I is more effective than E&I combined.