[R-meta] correlation between pre and post test?
ph|||ppet@dger @end|ng |rom gm@||@com
Thu Aug 26 11:12:43 CEST 2021
Yes, you can use the SMD of the post-measures, but it's the least
interesting option (because you drop information).
For Riley alternative model you can use metamisc::riley
On 26/08/2021 04:52, YA wrote:
> Hi everyone,
> Thank you very much for the helpful suggestions.
> By 'If all the studies present pre and post (and you don't have any
> study with change score) you can do a SMD only using the post
> measures', do you mean use post SD as the standardizer to calculate
> the SMD?
> 1. If I use change scores as the effect size, can I use the pre and
> post means and SDs to calculate the effect size and the standard error?
> 2. By using a range of plausible pre-post correlations for a
> sensitivity analysis, do you mean providing a correlation coefficient
> for all of primary studies and save the results, then change the
> correlation coefficient to another value for all the primary studies,
> and run the analysis again, see if the two sets of results are
> significantly different? Is it possible to do the significant test?
> I do not have access to SAS or Stata, do you know any R implementation
> example code using Riley(2008) method?
> Thank you very much guys.
> Best regards,
> *From:* "Philippe Tadger" <philippetadger using gmail.com>;
> *Date:*�Wed, Aug 25, 2021 08:54 PM
> Dewey"<lists using dewey.myzen.co.uk>;"YA"<xinxi813 using 126.com>;"r-sig-meta-analysis"<r-sig-meta-analysis using r-project.org>;
> *Subject:*�Re: [R-meta] correlation between pre and post test?
> Dear YA
> You can use correlation imputations from similar studies, or if this
> is not available you can use a mean difference estimation (not SMD)
> between the post and the change scores. If all the studies present pre
> and post (and you don't have any study with change score) you can do a
> SMD only using the post measures. All of this are common practices
> that you can find in Cochrane book, and basic MA books.
> On 25/08/2021 14:45, Michael Dewey wrote:
>> If you are planning to analyse the change scores you will be OK with
>> the mean change and its standard error. Otherwise try fitting with a
>> range of plausible correlations and see how sensitive the results are
>> to the assumed value.
>> On 25/08/2021 04:28, YA wrote:
>>> Dear list,
>>> I am trying to do meta analysis with random control trial research
>>> that has experiment and control group, and pre and post test.
>>> According to the meta analysis books, for these kind of research, I
>>> need the mean and SD for the experiment and control group at both
>>> pre and post test, I also need the correlation between pre and post
>>> test. The means and SDs are usually reported by the authors, but the
>>> correlations are usually not reported. How do I obtain the
>>> correlations between the pre and the post test?
>>> Thank you very much.
>>> Best regards,
>>> ����[[alternative HTML version deleted]]
>>> R-sig-meta-analysis mailing list
>>> R-sig-meta-analysis using r-project.org
> Kind regards/Saludos cordiales
> *Philippe Tadger*
> ORCID <https://orcid.org/0000-0002-1453-4105>, Reseach Gate
> Phone/WhatsApp: +32498774742
Kind regards/Saludos cordiales
ORCID <https://orcid.org/0000-0002-1453-4105>, Reseach Gate
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