metaSEM (version 1.2.4)

Hox02: Simulated Effect Sizes Reported by Hox (2002)

Description

Twenty stimulated studies on standardized mean difference and one continuous study characteristic reported by Hox (2002).

Usage

data(Hox02)

Details

The variables are:

study

Study number

yi

Effect size (standardized mean difference)

vi

Sampling variance of the effect size

weeks

Duration of the experimental intervention in terms of weeks

References

Cheung, M. W.-L. (2008). A model for integrating fixed-, random-, and mixed-effects meta-analyses into structural equation modeling. Psychological Methods, 13, 182-202.

Examples

# NOT RUN {
data(Hox02)

#### ML estimation method
## Random-effects meta-analysis
summary( meta(y=yi, v=vi, data=Hox02, I2=c("I2q", "I2hm"), intervals.type="LB") ) 

## Fixed-effects meta-analysis
summary( meta(y=yi, v=vi, data=Hox02, RE.constraints=0,
              model.name="Fixed effects model") )

## Mixed-effects meta-analysis with "weeks" as a predictor
## Request likelihood-based CI
summary( meta(y=yi, v=vi, x=weeks, data=Hox02, intervals.type="LB",
              model.name="Mixed effects meta analysis with LB CI") )

#### REML estimation method
## Random-effects meta-analysis with REML
summary( VarComp <- reml(y=yi, v=vi, data=Hox02) )

## Extract the variance component
VarComp_REML <- matrix( coef(VarComp), ncol=1, nrow=1 )

## Meta-analysis by treating the variance component as fixed
summary( meta(y=yi, v=vi, data=Hox02, RE.constraints=VarComp_REML) )


## Mixed-effects meta-analysis with "weeks" as a predictor
## Request Wald CI
summary( reml(y=yi, v=vi, x=weeks, intervals.type="z",
              data=Hox02, model.name="REML with LB CI") )
# }