A General Model for Testing Mediation and Moderation Effects

Department of Psychology, University of South Carolina, Barnwell College, 1512 Pendleton St., Columbia, SC 29208, USA.
Prevention Science (Impact Factor: 3.15). 12/2008; 10(2):87-99. DOI: 10.1007/s11121-008-0109-6
Source: PubMed


This paper describes methods for testing mediation and moderation effects in a dataset, both together and separately. Investigations of this kind are especially valuable in prevention research to obtain information on the process by which a program achieves its effects and whether the program is effective for subgroups of individuals. A general model that simultaneously estimates mediation and moderation effects is presented, and the utility of combining the effects into a single model is described. Possible effects of interest in the model are explained, as are statistical methods to assess these effects. The methods are further illustrated in a hypothetical prevention program example.

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    • "When testing mediation models, we first had to adjust parameter estimates for scaling differences between logistic and linear regression analyses as outlined by MacKinnon & Dwyer [34]. Next, we followed steps outlined by Fairchild and MacKinnon [35] to test for mediation. Specifically, three regression models were conducted: "
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