{smcl} {* *! version 2.0 05may2021}{...} {viewerdialog mareg "dialog mareg"}{...} {marker syntax}{...} {title:Syntax} {phang} Fixed- and random-effects inverse-variance weighted meta-analytic regression (aka: meta-regression). {p 8 16 2} {cmd:mareg} {effectsizevar} {indepvars} {ifin} {cmd:,} {opt var(varname)} {opt w(varname)} {opt se(varname)} [_options_] {pstd} where {it:effectsize} is the effect size variable and {it:indepvar} is one or more independent variable (moderator). The {it:effect size} can be any effect size type, such as Cohen's {it:d}, Hedges' {it:g}, logged odds ratio, logged risk ratio, logged logit, {it:r} or Fisher's {it:Zr}, among others. It is critical that the effect size is in its analyzable form. For example, the effect size can be a logged odds ratio but not an odds ratio. One of the following must also be specified: {phang2} o {it:var({varname})}: the variance of the effect size {phang2} o {it:w({varname})}: the inverse variance weight of the effect size {phang2} o {it:se({varname})}: the standard error of the effect size {pstd} The relationship among these is assumed to be {it:w} = 1/{it:var} = 1/{it:se^2}. {p_end} {marker reoptions}{...} {synoptset 20 tabbed}{...} {synopthdr :Options} {synoptline} {syntab:Model Type} {synopt :{opt model(_string_)}} model type; default is REML (restricted maximum likelihood); options include FE (fixed effect), DL (Dersimonian & Laird), HE (Hedges'), HS (Hunter & Schmidt), SJ (Sidik-Jonkman), SJIT (Sidik-Jonkman, iterative), ML (maximum likelihood), REML (restricted maximum likelihood), and EB (empirical bayes) {p_end} {marker description}{...} {title:Description} {pstd} {cmd:mareg} performs meta-analytic regression (aka: meta-regression, moderator analysis) under either a fixed-effect model (also called a common-effect model) or a random-effects model. Several estimators for the random effects variance component (tau^2) are available. The command requires an effect size, its associated standard error, variance, or inverse variance weight, and a one or more independent variables. {pstd} Subgroup or categorical moderator analysis (i.e., analog-to-the-ANOVA) can be performed with the {cmd:maanova} command (see {help maanova}). For a basic meta-analysis returning the overall mean effect size and associated statistics, see {cmd:masum} command (see {help masum}). {pstd} As of Stata version 16.0, Stata has a built-in command for conducting meta-analysis. See {help meta}. {marker description}{...} {title:Acknowledgments} {pstd} {cmd:mareg} was written by David B. Wilson and is an updated version of a command written as a companion to a book on meta-analysis he co-authored with Mark Lipsey (Lipsey & Wilson, 2001). Portions of this program are based on code from Wolfgang Viechtbauer's {it:metafor} package for R. {marker description}{...} {title:References} {pstd} Lipsey, M. W., & Wilson, D. B. (2001). {it} Practical meta-analysis. {sf} Sage.