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st: Question regarding Trim and Fill method using 'metatrim'
From
Chan Yoon <[email protected]>
To
"[email protected]" <[email protected]>
Subject
st: Question regarding Trim and Fill method using 'metatrim'
Date
Sat, 4 Sep 2010 12:02:27 +0900
> Hi. I am having trouble using stata in meta-analysis.
>
> I have used total 13 studies in my meta-analysis usig Random-effects model. Pulled estimate was 0.852 with 95% confidene interval (0.762 - 0.952)
> using Egger's test, p value is 0.174 which suggests publication bias with little statistical significance.
> however,although little publication bias in Egger;s test, funnel plot looked somewhat asymmetric so we decided to use Trim and Fill method to attain adjusted estimate.
>
> using commend as follows
>
> metatrim rr ll ul, ci eform reffect
>
> and result came out as follows
>
> Note: option 'ci' specified.
> Meta-analysis
>
> | Pooled 95% CI Asymptotic No. of
> Method | Est Lower Upper z_value p_value studies
> -------+----------------------------------------------------
> Fixed | -0.102 -0.151 -0.053 -4.120 0.000 13
> Random | -0.160 -0.271 -0.050 -2.838 0.005
>
> Test for heterogeneity: Q= 41.214 on 12 degrees of freedom (p= 0.000)
> Moment-based estimate of between studies variance = 0.023
>
> Trimming estimator: Linear
> Meta-analysis type: Random-effects model
> iteration | estimate Tn # to trim diff
> ----------+--------------------------------------
> 1 | -0.160 41 0 91
> 2 | -0.160 41 0 0
> Note: no trimming performed; data unchanged
>
> Filled
> Meta-analysis (exponential form)
> | Pooled 95% CI Asymptotic No. of
> Method | Est Lower Upper z_value p_value studies
> -------+----------------------------------------------------
> Fixed | 0.903 0.860 0.948 -4.120 0.000 13
> Random | 0.852 0.762 0.952 -2.838 0.005
> Test for heterogeneity: Q= 41.214 on 12 degrees of freedom (p= 0.000)
> Moment-based estimate of between studies variance = 0.023
>
> -------------------------------------------------------------------------------------------------------------
>
> I have used metatrim with other dataset before and it added some studies to reduce the asymmetric funnel plot.
> with additional studies filled meta-analysis showed publication bias adjusted pulled estimate.
>
> However, using this dataset, to trimming performed and data unchanged. I think even egger;s test showes insignificant publication bias, there should be some cahnge in the estimate using trima nd fill method. so.. I believed there is something wrong in the way I used 'metatrim'.
>
> I would really appreciate some help by experts. Thank you very much for readling this long question.
>
>
>
>
>
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