<html><head></head><body><div style="font-family: Verdana;font-size: 12.0px;"><div>Dear Wolfgang, at all</div>
<div> </div>
<div>sorry for that.</div>
<div> </div>
<div>I thought this might also a way to do it. Or am I way off?</div>
<div>
<p><span style="font-size:11pt"><span style="line-height:normal"><span style="tab-stops:45.8pt 91.6pt 137.4pt 183.2pt 229.0pt 274.8pt 320.6pt 366.4pt 412.2pt 458.0pt 503.8pt 549.6pt 595.4pt 641.2pt 687.0pt 732.8pt"><span style="font-family:Calibri,sans-serif"><span lang="EN-US" style="font-size:9.0pt"><span style="font-family:"Verdana",sans-serif"><span style="color:black">Between-group change score from baseline to follow-up (9 months) is 1.8(-</span></span></span><br style="font-variant-ligatures:normal; font-variant-caps:normal; orphans:2; text-align:start; widows:2; -webkit-text-stroke-width:0px; text-decoration-style:initial; text-decoration-color:initial; word-spacing:0px"/>
<span style="font-variant-ligatures:normal; text-align:start; -webkit-text-stroke-width:0px"><span style="font-variant-caps:normal"><span style="orphans:2"><span style="widows:2"><span style="text-decoration-style:initial"><span style="text-decoration-color:initial"><span style="float:none"><span style="word-spacing:0px">5.7, 9.3) (mean and 95%CI) and p-value 0.64; </span></span></span></span></span></span></span></span><span style="font-variant-ligatures:normal; text-align:start; -webkit-text-stroke-width:0px"><span style="font-variant-caps:normal"><span style="orphans:2"><span style="widows:2"><span style="text-decoration-style:initial"><span style="text-decoration-color:initial"><span style="float:none"><span style="word-spacing:0px">Sample size is n1 = 30; n2 = 36 (two group RCT).</span></span></span></span></span></span></span></span></span></span></span></span></p>
<p><span style="font-size:11pt"><span style="line-height:normal"><span style="tab-stops:45.8pt 91.6pt 137.4pt 183.2pt 229.0pt 274.8pt 320.6pt 366.4pt 412.2pt 458.0pt 503.8pt 549.6pt 595.4pt 641.2pt 687.0pt 732.8pt"><span style="font-family:Calibri,sans-serif"><span lang="EN-US" style="border:none windowtext 1.0pt; font-size:10.0pt; padding:0cm"><span style="font-family:Consolas"><span style="color:#333333"><span style="letter-spacing:.15pt">require(dmetar)</span></span></span></span></span></span></span></span></p>
<p><span style="font-size:11pt"><span style="line-height:normal"><span style="tab-stops:45.8pt 91.6pt 137.4pt 183.2pt 229.0pt 274.8pt 320.6pt 366.4pt 412.2pt 458.0pt 503.8pt 549.6pt 595.4pt 641.2pt 687.0pt 732.8pt"><span style="font-family:Calibri,sans-serif"><span lang="EN-US" style="border:none windowtext 1.0pt; font-size:10.0pt; padding:0cm"><span style="font-family:Consolas"><span style="color:#333333"><span style="letter-spacing:.15pt">require(esc)</span></span></span></span></span></span></span></span></p>
<p><span style="font-size:24pt"><span style="background:white"><span style="font-family:"Times New Roman",serif"><span lang="EN-US" style="border:none windowtext 1.0pt; font-size:10.0pt; padding:0cm"><span style="font-family:Consolas"><span style="color:#333333"><span style="letter-spacing:.15pt">#### </span></span></span></span><span lang="EN-US" style="font-size:11.0pt"><span style="font-family:"Calibri",sans-serif"><span style="color:#2c3e50"><span style="font-weight:normal">Calculate the standard error from the effect size and p-value ####</span></span></span></span></span></span></span></p>
<p><span style="font-size:11pt"><span style="background:white"><span style="line-height:normal"><span style="tab-stops:45.8pt 91.6pt 137.4pt 183.2pt 229.0pt 274.8pt 320.6pt 366.4pt 412.2pt 458.0pt 503.8pt 549.6pt 595.4pt 641.2pt 687.0pt 732.8pt"><span style="word-break:break-all"><span style="font-family:Calibri,sans-serif"><span lang="EN-US" style="font-size:10.0pt"><span style="font-family:"Lucida Console""><span style="color:blue">se.from.p(effect.size = 1.88, p = 0.64, N = 66,effect.size.type= "difference", calculate.g = FALSE)</span></span></span></span></span></span></span></span></span></p>
<p><span style="font-size:11pt"><span style="background:white"><span style="line-height:normal"><span style="tab-stops:45.8pt 91.6pt 137.4pt 183.2pt 229.0pt 274.8pt 320.6pt 366.4pt 412.2pt 458.0pt 503.8pt 549.6pt 595.4pt 641.2pt 687.0pt 732.8pt"><span style="word-break:break-all"><span style="font-family:Calibri,sans-serif"><span lang="EN-US" style="font-size:10.0pt"><span style="font-family:"Lucida Console""><span style="color:blue">#### Results####</span></span></span></span></span></span></span></span></span></p>
<p><span style="font-size:11pt"><span style="background:white"><span style="line-height:normal"><span style="tab-stops:45.8pt 91.6pt 137.4pt 183.2pt 229.0pt 274.8pt 320.6pt 366.4pt 412.2pt 458.0pt 503.8pt 549.6pt 595.4pt 641.2pt 687.0pt 732.8pt"><span style="word-break:break-all"><span style="font-family:Calibri,sans-serif"><span lang="EN-US" style="border:none windowtext 1.0pt; font-size:10.0pt; padding:0cm"><span style="font-family:"Lucida Console""><span style="color:black">EffectSize StandardError StandardDeviation LLCI ULCI</span></span></span></span></span></span></span></span></span></p>
<p><span style="font-size:11pt"><span style="background:white"><span style="line-height:normal"><span style="tab-stops:45.8pt 91.6pt 137.4pt 183.2pt 229.0pt 274.8pt 320.6pt 366.4pt 412.2pt 458.0pt 503.8pt 549.6pt 595.4pt 641.2pt 687.0pt 732.8pt"><span style="word-break:break-all"><span style="font-family:Calibri,sans-serif"><span lang="EN-US" style="border:none windowtext 1.0pt; font-size:10.0pt; padding:0cm"><span style="font-family:"Lucida Console""><span style="color:black">1 1.88 3.871948 31.45585 -5.709017 9.469017</span></span></span></span></span></span></span></span></span></p>
<p><span style="font-size:11pt"><span style="background:white"><span style="line-height:normal"><span style="tab-stops:45.8pt 91.6pt 137.4pt 183.2pt 229.0pt 274.8pt 320.6pt 366.4pt 412.2pt 458.0pt 503.8pt 549.6pt 595.4pt 641.2pt 687.0pt 732.8pt"><span style="word-break:break-all"><span style="font-family:Calibri,sans-serif"><span lang="EN-US" style="font-size:10.0pt"><span style="font-family:"Lucida Console""><span style="color:blue">##### Assume that r = 0.5 (conservative) => SD_change = SD_pre_post * sqrt(2*0.5) ####</span></span></span></span></span></span></span></span></span></p>
<p><span style="font-size:10pt"><span style="background:white"><span style="word-break:break-all"><span style="font-family:"Courier New""><span lang="EN-US" style="font-family:"Lucida Console""><span style="color:blue">esc_mean_se(grp1m = 1.88, grp1se = </span></span><span lang="EN-US" style="border:none windowtext 1.0pt; font-family:"Lucida Console"; padding:0cm"><span style="color:black">3.871948</span></span><span lang="EN-US" style="font-family:"Lucida Console""><span style="color:blue">, grp1n = 30,</span></span></span></span></span></span></p>
<pre><span style="font-size:10pt"><span style="background:white"><span style="word-break:break-all"><span style="font-family:"Courier New""><span lang="EN-US" style="font-family:"Lucida Console""><span style="color:blue">grp2m = 0, grp2se = </span></span><span lang="EN-US" style="border:none windowtext 1.0pt; font-family:"Lucida Console"; padding:0cm"><span style="color:black">3.871948 </span></span><span lang="EN-US" style="font-family:"Lucida Console""><span style="color:blue">, grp2n = 36, es.type = "g")</span></span></span></span></span></span></pre>
<p><span style="font-size:11pt"><span style="line-height:normal"><span style="tab-stops:45.8pt 91.6pt 137.4pt 183.2pt 229.0pt 274.8pt 320.6pt 366.4pt 412.2pt 458.0pt 503.8pt 549.6pt 595.4pt 641.2pt 687.0pt 732.8pt"><span style="font-family:Calibri,sans-serif"><span lang="EN-US" style="border:none windowtext 1.0pt; font-size:10.0pt; padding:0cm"><span style="font-family:Consolas"><span style="color:#333333"><span style="letter-spacing:.15pt">#### Results ####</span></span></span></span></span></span></span></span></p>
<p><span style="font-size:11pt"><span style="background:white"><span style="line-height:normal"><span style="tab-stops:45.8pt 91.6pt 137.4pt 183.2pt 229.0pt 274.8pt 320.6pt 366.4pt 412.2pt 458.0pt 503.8pt 549.6pt 595.4pt 641.2pt 687.0pt 732.8pt"><span style="word-break:break-all"><span style="font-family:Calibri,sans-serif"><span lang="EN-US" style="border:none windowtext 1.0pt; font-size:10.0pt; padding:0cm"><span style="font-family:"Lucida Console""><span style="color:black">Effect Size Calculation for Meta Analysis</span></span></span></span></span></span></span></span></span></p>
<p> </p>
<p><span style="font-size:11pt"><span style="background:white"><span style="line-height:normal"><span style="tab-stops:45.8pt 91.6pt 137.4pt 183.2pt 229.0pt 274.8pt 320.6pt 366.4pt 412.2pt 458.0pt 503.8pt 549.6pt 595.4pt 641.2pt 687.0pt 732.8pt"><span style="word-break:break-all"><span style="font-family:Calibri,sans-serif"><span lang="EN-US" style="border:none windowtext 1.0pt; font-size:10.0pt; padding:0cm"><span style="font-family:"Lucida Console""><span style="color:black"> Conversion: mean and se to effect size Hedges' g</span></span></span></span></span></span></span></span></span></p>
<p><span style="font-size:11pt"><span style="background:white"><span style="line-height:normal"><span style="tab-stops:45.8pt 91.6pt 137.4pt 183.2pt 229.0pt 274.8pt 320.6pt 366.4pt 412.2pt 458.0pt 503.8pt 549.6pt 595.4pt 641.2pt 687.0pt 732.8pt"><span style="word-break:break-all"><span style="font-family:Calibri,sans-serif"><span lang="EN-US" style="border:none windowtext 1.0pt; font-size:10.0pt; padding:0cm"><span style="font-family:"Lucida Console""><span style="color:black"> Effect Size: 0.0845</span></span></span></span></span></span></span></span></span></p>
<p><span style="font-size:11pt"><span style="background:white"><span style="line-height:normal"><span style="tab-stops:45.8pt 91.6pt 137.4pt 183.2pt 229.0pt 274.8pt 320.6pt 366.4pt 412.2pt 458.0pt 503.8pt 549.6pt 595.4pt 641.2pt 687.0pt 732.8pt"><span style="word-break:break-all"><span style="font-family:Calibri,sans-serif"><span lang="EN-US" style="border:none windowtext 1.0pt; font-size:10.0pt; padding:0cm"><span style="font-family:"Lucida Console""><span style="color:black"> Standard Error: 0.2473</span></span></span></span></span></span></span></span></span></p>
<p><span style="font-size:11pt"><span style="background:white"><span style="line-height:normal"><span style="tab-stops:45.8pt 91.6pt 137.4pt 183.2pt 229.0pt 274.8pt 320.6pt 366.4pt 412.2pt 458.0pt 503.8pt 549.6pt 595.4pt 641.2pt 687.0pt 732.8pt"><span style="word-break:break-all"><span style="font-family:Calibri,sans-serif"><span lang="EN-US" style="border:none windowtext 1.0pt; font-size:10.0pt; padding:0cm"><span style="font-family:"Lucida Console""><span style="color:black"> Variance: 0.0612</span></span></span></span></span></span></span></span></span></p>
<p><span style="font-size:11pt"><span style="background:white"><span style="line-height:normal"><span style="tab-stops:45.8pt 91.6pt 137.4pt 183.2pt 229.0pt 274.8pt 320.6pt 366.4pt 412.2pt 458.0pt 503.8pt 549.6pt 595.4pt 641.2pt 687.0pt 732.8pt"><span style="word-break:break-all"><span style="font-family:Calibri,sans-serif"><span lang="EN-US" style="border:none windowtext 1.0pt; font-size:10.0pt; padding:0cm"><span style="font-family:"Lucida Console""><span style="color:black"> Lower CI: -0.4003</span></span></span></span></span></span></span></span></span></p>
<p><span style="font-size:11pt"><span style="background:white"><span style="line-height:normal"><span style="tab-stops:45.8pt 91.6pt 137.4pt 183.2pt 229.0pt 274.8pt 320.6pt 366.4pt 412.2pt 458.0pt 503.8pt 549.6pt 595.4pt 641.2pt 687.0pt 732.8pt"><span style="word-break:break-all"><span style="font-family:Calibri,sans-serif"><span lang="EN-US" style="border:none windowtext 1.0pt; font-size:10.0pt; padding:0cm"><span style="font-family:"Lucida Console""><span style="color:black"> Upper CI: 0.5692</span></span></span></span></span></span></span></span></span></p>
<p><span style="font-size:11pt"><span style="background:white"><span style="line-height:normal"><span style="tab-stops:45.8pt 91.6pt 137.4pt 183.2pt 229.0pt 274.8pt 320.6pt 366.4pt 412.2pt 458.0pt 503.8pt 549.6pt 595.4pt 641.2pt 687.0pt 732.8pt"><span style="word-break:break-all"><span style="font-family:Calibri,sans-serif"><span lang="EN-US" style="border:none windowtext 1.0pt; font-size:10.0pt; padding:0cm"><span style="font-family:"Lucida Console""><span style="color:black"> Weight: 16.3488</span></span></span></span></span></span></span></span></span></p>
<p> </p>
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<div name="quote" style="margin:10px 5px 5px 10px; padding: 10px 0 10px 10px; border-left:2px solid #C3D9E5; word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;">
<div style="margin:0 0 10px 0;"><b>Gesendet:</b> Dienstag, 18. August 2020 um 08:50 Uhr<br/>
<b>Von:</b> "Viechtbauer, Wolfgang (SP)" <wolfgang.viechtbauer@maastrichtuniversity.nl><br/>
<b>An:</b> "Tobias Saueressig" <t.saueressig@gmx.de><br/>
<b>Cc:</b> "r-sig-meta-analysis@r-project.org" <r-sig-meta-analysis@r-project.org><br/>
<b>Betreff:</b> RE: RE: [R-meta] Data Extraction</div>
<div name="quoted-content">Please always cc the mailing list.<br/>
<br/>
You can include the study if you know (or can guestimate) the pre-post correlation.<br/>
<br/>
SD of the change scores = SD * sqrt(2*(1-r)),<br/>
<br/>
where SD is the pre or post treatment SD (this assumes that the SD is the same before and after the treatment). So if you know r, you can easily recover the SD and standardize in the usual manner.<br/>
<br/>
Best,<br/>
Wolfgang<br/>
<br/>
>-----Original Message-----<br/>
>From: Tobias Saueressig [mailto:t.saueressig@gmx.de]<br/>
>Sent: Tuesday, 18 August, 2020 7:40<br/>
>To: Viechtbauer, Wolfgang (SP)<br/>
>Subject: Aw: RE: [R-meta] Data Extraction<br/>
><br/>
>Dear Wolfgang,<br/>
><br/>
>you are my hero. Thank you.<br/>
><br/>
>I am a bit sad that I cannot include the study because it is based on change<br/>
>scores and I have used postintervention only.<br/>
><br/>
>Gesendet: Montag, 17. August 2020 um 22:33 Uhr<br/>
>Von: "Viechtbauer, Wolfgang (SP)"<br/>
><wolfgang.viechtbauer@maastrichtuniversity.nl><br/>
>An: "Tobias Saueressig" <t.saueressig@gmx.de>, "r-sig-meta-analysis@r-<br/>
>project.org" <r-sig-meta-analysis@r-project.org><br/>
>Betreff: RE: [R-meta] Data Extraction<br/>
>Dear Tobias,<br/>
><br/>
>The difference between the upper and lower CI bounds divided by the<br/>
>appropriate critical t-value should be *twice* the SE. So:<br/>
><br/>
>SE <- (9.3 - -5.7) / (2*1.99)<br/>
><br/>
>should be the SE of the difference in the mean change between the two<br/>
>groups. Dividing this by sqrt(1/n1 + 1/n2) should give you the SD of the<br/>
>change scores (assuming homoscedasticity of the change variances in the two<br/>
>groups), so:<br/>
><br/>
>SD <- SE / sqrt(1/30 + 1/36)<br/>
><br/>
>Hence:<br/>
><br/>
>1.8/SD<br/>
><br/>
>yields approximately 0.12. Sure you can apply the bias correction, but this<br/>
>is hardly relevant here.<br/>
><br/>
>More importantly, this d-value standardizes the difference between the two<br/>
>groups based on the (pooled) SD of the change scores. This is not comparable<br/>
>to d-values that use the SD of a single time point for the standardization.<br/>
><br/>
>Best,<br/>
>Wolfgang<br/>
><br/>
>>-----Original Message-----<br/>
>>From: R-sig-meta-analysis [mailto:r-sig-meta-analysis-bounces@r-<br/>
>project.org]<br/>
>>On Behalf Of Tobias Saueressig<br/>
>>Sent: Monday, 17 August, 2020 12:03<br/>
>>To: r-sig-meta-analysis@r-project.org<br/>
>>Subject: [R-meta] Data Extraction<br/>
>><br/>
>>Hello,<br/>
>><br/>
>>I have a problem to extract data from one study. I want to calculate<br/>
>hedges<br/>
>>g.<br/>
>><br/>
>>I have the following information (2 groups):<br/>
>><br/>
>>Between-group change score from baseline to follow-up (9 months) is 1.8(-<br/>
>>5.7,9.3) (mean and 95%CI) and p-value 0.64<br/>
>><br/>
>>Sample size is n1 = 30; n2 = 36 (two group RCT).<br/>
>><br/>
>>Link: <a href="https://linkinghub.elsevier.com/retrieve/pii/S1063458420309882" target="_blank">https://linkinghub.elsevier.com/retrieve/pii/S1063458420309882</a> (TABLE<br/>
>>2 HOOS ADL)<br/>
>><br/>
>>I would do it the following way:<br/>
>><br/>
>>Calculate a SD for both group from the CI. _> SE = (Upper limit-lower<br/>
>>limit)/t-statistic (~2) => SD = SE/squ(1/n1 + 1/n2)<br/>
>><br/>
>>Then g = d = MD/SD<br/>
>><br/>
>>g* = (1-3/(4*(n1+n2)-9) * g<br/>
>><br/>
>>e.g.<br/>
>><br/>
>>SE = (9.3+5.7)/1.99 = 7.54 => SD = 7.54/squ(1/30+1/36) = 7.54/0.25 = 30.16<br/>
>><br/>
>>g = 1.8/30.16 = 0.06<br/>
>><br/>
>>g* = 0.06 * (1-3/255) = 0.06 * 0.99 = 0.0594<br/>
>><br/>
>>Is that correct?<br/>
>><br/>
>>Best regards<br/>
>><br/>
>>Tobias</div>
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