analyses:vanhouwelingen2002
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analyses:vanhouwelingen2002 [2021/05/09 15:38] – Wolfgang Viechtbauer | analyses:vanhouwelingen2002 [2021/10/22 15:29] – Wolfgang Viechtbauer | ||
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dat | dat | ||
</ | </ | ||
- | (I copy the dataset into ' | + | (I copy the dataset into ''dat'', which is a bit shorter and therefore easier to type further below). Variables '' |
We can calculate the individual log odds ratios and corresponding sampling variances with: | We can calculate the individual log odds ratios and corresponding sampling variances with: | ||
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abline(h=x[2]) | abline(h=x[2]) | ||
</ | </ | ||
+ | |||
+ | While the coefficient (i.e., 0.7300) of the relationship between the underlying true log odds in the vaccinated and unvaccinated groups obtained above is correct, the computation of the corresponding standard error is not quite right, as it assumes that the variance-covariance matrix used as input to '' | ||
+ | |||
+ | <code rsplus> | ||
+ | res <- rma.mv(yi, vi, mods = ~ group - 1, random = ~ group | trial, struct=" | ||
+ | </ | ||
+ | |||
+ | Now '' | ||
+ | |||
+ | <code rsplus> | ||
+ | res$vvc | ||
+ | </ | ||
+ | <code output> | ||
+ | tau^2.1 | ||
+ | tau^2.1 0.9359073 0.6711028 0.4822374 | ||
+ | cov | ||
+ | tau^2.2 0.4822374 0.4066553 0.3399395 | ||
+ | </ | ||
+ | |||
+ | We can then use this matrix as part of the input to '' | ||
+ | |||
+ | <code rsplus> | ||
+ | matreg(y=2, x=1, R=res$G, cov=TRUE, means=coef(res), | ||
+ | </ | ||
+ | |||
+ | <code output> | ||
+ | | ||
+ | intrcpt | ||
+ | CON 0.7300 | ||
+ | </ | ||
+ | |||
+ | Now the standard error of the coefficient of interest is computed in such a way that it correctly takes the imprecision of the estimates in '' | ||
==== Meta-Regression ==== | ==== Meta-Regression ==== |
analyses/vanhouwelingen2002.txt · Last modified: 2022/08/03 17:52 by Wolfgang Viechtbauer