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Stata Textbook Examples
Multilevel Analysis Techniques and Applications by Joop Hox
Chapter 8: The Multilevel Approach to Meta-Analysis

Table 8.3 on page 148 using meta20.dta.
use http://www.ats.ucla.edu/stat/stata/examples/mlm_ma_hox/meta20, clear

metareg d, wsvar(varofd)

Iteration 1: tau^2 = 0
Iteration 2: tau^2 = .10394204
Iteration 3: tau^2 = .1391358
Iteration 4: tau^2 = .14386754
Iteration 5: tau^2 = .14439935
Meta-analysis regression                               No of studies =   20
                                                       tau^2 method      reml
                                                       tau^2 estimate =  .1445
Successive values of tau^2 differ by less than 10^-4 :convergence achieved
------------------------------------------------------------------------------
             |      Coef.   Std. Err.      z    P>|z|     [95% Conf. Interval]
-------------+----------------------------------------------------------------
       _cons |   .5801336   .1079661     5.37   0.000     .3685238    .7917434
------------------------------------------------------------------------------

metareg d weeks, wsvar(varofd)

Iteration 1: tau^2 = 0
Iteration 2: tau^2 = .03136796
Iteration 3: tau^2 = .03571649
Iteration 4: tau^2 = .03614453
Meta-analysis regression                               No of studies =   20
                                                       tau^2 method      reml
                                                       tau^2 estimate =  .0362
Successive values of tau^2 differ by less than 10^-4 :convergence achieved
------------------------------------------------------------------------------
             |      Coef.   Std. Err.      z    P>|z|     [95% Conf. Interval]
-------------+----------------------------------------------------------------
       weeks |    .139891   .0337286     4.15   0.000     .0737842    .2059978
       _cons |  -.2168592   .2039623    -1.06   0.288    -.6166179    .1828996
------------------------------------------------------------------------------
Table 8.4 on page 151.
metareg d, wsvar(varofd)

Meta-analysis regression                               No of studies =   20
                                                       tau^2 method      reml
                                                       tau^2 estimate =  .1445
Successive values of tau^2 differ by less than 10^-4 :convergence achieved
------------------------------------------------------------------------------
             |      Coef.   Std. Err.      z    P>|z|     [95% Conf. Interval]
-------------+----------------------------------------------------------------
       _cons |   .5801336   .1079661     5.37   0.000     .3685238    .7917434
------------------------------------------------------------------------------

metareg d ntot, wsvar(varofd)

Iteration 1: tau^2 = 0
Iteration 2: tau^2 = .11468708
Iteration 3: tau^2 = .15297015
Iteration 4: tau^2 = .15770374
Iteration 5: tau^2 = .15819142
Meta-analysis regression                               No of studies =   20
                                                       tau^2 method      reml
                                                       tau^2 estimate =  .1582
Successive values of tau^2 differ by less than 10^-4 :convergence achieved
------------------------------------------------------------------------------
             |      Coef.   Std. Err.      z    P>|z|     [95% Conf. Interval]
-------------+----------------------------------------------------------------
        ntot |   .0024866   .0089872     0.28   0.782     -.015128    .0201013
       _cons |   .4430318   .5115285     0.87   0.386    -.5595457    1.445609
------------------------------------------------------------------------------

metareg d rii, wsvar(varofd)

Iteration 1: tau^2 = 0
Iteration 2: tau^2 = .10891042
Iteration 3: tau^2 = .14966556
Iteration 4: tau^2 = .1554571
Iteration 5: tau^2 = .15612963
Meta-analysis regression                               No of studies =   20
                                                       tau^2 method      reml
                                                       tau^2 estimate =  .1562
Successive values of tau^2 differ by less than 10^-4 :convergence achieved
------------------------------------------------------------------------------
             |      Coef.   Std. Err.      z    P>|z|     [95% Conf. Interval]
-------------+----------------------------------------------------------------
         rii |   .5088333   1.476465     0.34   0.730    -2.384984    3.402651
       _cons |   .1600426   1.226581     0.13   0.896    -2.244012    2.564098
------------------------------------------------------------------------------

metareg d  weeks, wsvar(varofd)

Iteration 1: tau^2 = 0
Iteration 2: tau^2 = .03136796
Iteration 3: tau^2 = .03571649
Iteration 4: tau^2 = .03614453
Meta-analysis regression                               No of studies =   20
                                                       tau^2 method      reml
                                                       tau^2 estimate =  .0362
Successive values of tau^2 differ by less than 10^-4 :convergence achieved
------------------------------------------------------------------------------
             |      Coef.   Std. Err.      z    P>|z|     [95% Conf. Interval]
-------------+----------------------------------------------------------------
       weeks |    .139891   .0337286     4.15   0.000     .0737842    .2059978
       _cons |  -.2168592   .2039623    -1.06   0.288    -.6166179    .1828996
------------------------------------------------------------------------------

metareg d ntot rii weeks, wsvar(varofd)

Iteration 1: tau^2 = 0
Iteration 2: tau^2 = .03946844
Iteration 3: tau^2 = .04664761
Iteration 4: tau^2 = .04741679
Meta-analysis regression                               No of studies =   20
                                                       tau^2 method      reml
                                                       tau^2 estimate =  .0475
Successive values of tau^2 differ by less than 10^-4 :convergence achieved
------------------------------------------------------------------------------
             |      Coef.   Std. Err.      z    P>|z|     [95% Conf. Interval]
-------------+----------------------------------------------------------------
        ntot |  -.0035676   .0069797    -0.51   0.609    -.0172475    .0101123
         rii |  -.5499779   1.192699    -0.46   0.645    -2.887626     1.78767
       weeks |   .1504684   .0372957     4.03   0.000     .0773701    .2235667
       _cons |   .3837634    .917115     0.42   0.676    -1.413749    2.181276
------------------------------------------------------------------------------

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