ABSTRACT
Continuing from Chapter 6 to explain heterogeneity in meta-analysis, we ex-
plore meta-regression in this chapter to explain extra heterogeneity (or the
residual heterogeneity) using study-level moderators or study-level indepen-
dent variables. With study-level moderators associated with the reported effect
sizes as the dependent variable and their variance as weights, typical weighted
regression analysis methods can be utilized. From this point of view, meta-
regression is merely typical multiple regression applied for study-level data and
therefore the theory of regression can be directly applied for meta-regression.
