Post-hoc probing of significant moderational and mediational effects in studies of pediatric populations

J Pediatr Psychol. 2002 Jan-Feb;27(1):87-96. doi: 10.1093/jpepsy/27.1.87.

Abstract

Objective: To provide examples of post-hoc probing of significant moderator and mediator effects in research on children with pediatric conditions.

Methods: To demonstrate post-hoc probing of moderational effects, significant two-way interaction effects (dichotomous variable x continuous variable; continuous variable x continuous variable) were probed with regressions that included conditional moderator variables. Regression lines were plotted based on the resulting regression equations that included simple slopes and y-intercepts. To demonstrate probing of mediational effects, the significance of the indirect effect was tested (i.e., the drop in the total predictor --> outcome effect when the mediator is included in the model), using Sobel's (1988) equation for computing the standard error of the indirect effect.

Results: All significant moderator and mediator effects are presented in figure form.

Conclusions: The computational examples demonstrate the importance of conducting post-hoc probes of moderational and mediational effects.

Publication types

  • Research Support, Non-U.S. Gov't
  • Review

MeSH terms

  • Adolescent
  • Child
  • Data Interpretation, Statistical*
  • Effect Modifier, Epidemiologic*
  • Humans
  • Parenting
  • Psychology, Adolescent / statistics & numerical data*
  • Psychology, Child / statistics & numerical data*
  • Regression Analysis
  • Spinal Dysraphism / psychology