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Published on: September 17, 2019
Direct and indirect effects for neighborhood-based clustered and longitudinal data
1Dept. of Epidemiology, Harvard School of Public Health, 677 Huntington Ave., Boston, MA 02115, tvanderw@hsph.harvard.edu.
This study defines direct and indirect effects for group-level interventions, considering how treatments impact individuals and their environment. It provides conditions for identifying these effects in neighborhood research and multilevel modeling.
Area of Science:
- Causal inference
- Epidemiology
- Social and behavioral sciences
Background:
- Interventions are often administered at the group level (e.g., neighborhoods).
- Individual outcomes can be influenced directly and indirectly through group-level changes.
- Existing causal inference methods may not fully capture these complex group-level dynamics.
Purpose of the Study:
- To define direct and indirect effects in clustered settings with group-level treatments.
- To establish identification conditions for controlled direct effects and natural direct/indirect effects.
- To explore the application of these definitions in neighborhood research and multilevel modeling.
Main Methods:
- Development of causal definitions for direct and indirect effects in clustered data.
- Formulation of identification conditions for various effect types.
- Consideration of both single-point-in-time and time-varying interventions.
- Discussion of stability and no-interference assumptions and potential relaxations.
Main Results:
- Formal definitions for direct and indirect effects are provided for group-level interventions.
- Identification conditions are derived for controlled direct effects and natural direct/indirect effects.
- The framework accommodates complex interactions between individual and group-level influences.
Conclusions:
- The proposed definitions and identification conditions enhance causal inference in clustered settings.
- This work is particularly relevant for neighborhood research and multilevel modeling.
- The study offers a foundation for analyzing complex interventions with both individual and group-level pathways.
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