Tools and Tutorials
A tutorial on mediation analysis with SAS, SPSS, and Stata Macros:
Valeri, L. and VanderWeele, T.J. Mediation analysis allowing for exposure-mediator interactions and causal interpretation: theoretical assumptions and implementation with SAS and SPSS macros. Psychological Methods, in press.
An Excel spreadsheet to carry out power and sample size calculations for additive and multiplicative interactions (see Appendix 2 for instructions):
VanderWeele, T.J. (2012). Sample size and power calculations for additive interactions. Epidemiologic Methods, 1:159-188.