[R-meta] meta-analysis of ratios or ratios/ratios? can you help me ?

[Martin Lobo]

Hello everyone.
I'm going to expand the explanation to see if someone can help me. I want to investigate the changes in uCRP with a specific treatment vs placebo. The difficulty I have is that very few report this quantitative variable (uCRP). But I have found many papers that report the FINAL/BASAL relationship in both branches. From this data I came up with two strategies.
1- Analyze the FINAL/BASAL relationship in the two branches with their respective confidence intervals.
2- Analyze the ratio of ratios (FINAL/BASAL TREATMENT BRANCH / FINAL/BASAL PLACEBO BRANCH) in both branches with their respective confidence intervals.

I can't find how to analyze option one with metagen, since I can only enter the TE and the seTE. I don't know if with this data the two branches could be analyzed directly in some way or directly with metafor.
Although option 2 could be analyzed with metagen using OR or RR as effect measures, I would not know if it would be conceptually correct, since the data are the percentage changes of a continuous variable and not the proportion of binary events.
I would appreciate help with this analysis.

Have a great year everyone.

Martin from argentina



Lorenzo Martín Lobo MTSAC, FACC, FESC
Especialista Jerarquizado en Cardiología
Jefe de Dpto Enf. Cardiovasculares y Cardiometabolismo Hospital Militar Campo de Mayo.
Jefe de Cardiología Hospital Militar Campo de Mayo
Ex Jefe de Unidad Coronaria Hospital Militar Campo de Mayo
Miembro Titular de la Sociedad Argentina de Cardiología
Fellow American College of Cardiology
Fellow European Society of Cardiology
Ex Miembro del Area de Investigación de la SAC
Ex Director del Consejo de Aterosclerosis y Trombosis de la SAC
Miembro Asesor del Consejo de Aterosclerosis y Trombosis de la SAC
Ex Director del Consejo de Epidemiología y Prevención Cardiovascular de la SAC
Miembro Asesor del Consejo de Epidemiología y Prevención Cardiovascular de la SAC
Experto en Lipidos de la Sociedad Argentina de Lipidos.
Miembro de la Sociedad Argentina de Lipidos.
Instructor de ACLS de la American Heart Association


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Enviado: sábado, 23 de diciembre de 2023 08:00
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Asunto: R-sig-meta-analysis Digest, Vol 79, Issue 26

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Today's Topics:

   1. meta-analysis of ratios or difference of ratios? (Martin Lobo)

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Message: 1
Date: Fri, 22 Dec 2023 13:32:15 +0000
From: Martin Lobo <mlobo4370 using hotmail.com>
To: "r-sig-meta-analysis using r-project.org"
        <r-sig-meta-analysis using r-project.org>,
        "r-sig-meta-analysis-request using r-project.org"
        <r-sig-meta-analysis-request using r-project.org>, Gerta Ruecker
        <ruecker using imbi.uni-freiburg.de>
Subject: [R-meta] meta-analysis of ratios or difference of ratios?
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        <SA1P220MB089166F8BC935F568C8FEADFAC94A using SA1P220MB0891.NAMP220.PROD.OUTLOOK.COM>

Content-Type: text/plain; charset="utf-8"

Hello everyone. I'm Martin from Argentina. I am wanting to do a meta-analysis of the difference in means, baseline-final CRP drug vs pacebo. The problem is that complete data is not reported in most studies. Especially the standard deviation. What I have found is that they report the Final/baseline ratio in both groups. With these data you could calculate the difference in the ratios and their 95% CI. It is feasible to perform a meta-analysis with this data. My options would be meta-analysis of proportions (in this case I have the proportion but I don't know which one to use), perhaps another option would be the generic method of inverse variance where I would meta-analyze the difference in the proportions in both branches. Would any of these options be correct? Or can you tell me what would be the best method in this case? Thank you very much and happy holidays to all.




Lorenzo Mart�n Lobo MTSAC, FACC, FESC
Especialista Jerarquizado en Cardiolog�a
Jefe de Dpto Enf. Cardiovasculares y Cardiometabolismo Hospital Militar Campo de Mayo.
Jefe de Cardiolog�a Hospital Militar Campo de Mayo
Ex Jefe de Unidad Coronaria Hospital Militar Campo de Mayo
Miembro Titular de la Sociedad Argentina de Cardiolog�a
Fellow American College of Cardiology
Fellow European Society of Cardiology
Ex Miembro del Area de Investigaci�n de la SAC
Ex Director del Consejo de Aterosclerosis y Trombosis de la SAC
Miembro Asesor del Consejo de Aterosclerosis y Trombosis de la SAC
Ex Director del Consejo de Epidemiolog�a y Prevenci�n Cardiovascular de la SAC
Miembro Asesor del Consejo de Epidemiolog�a y Prevenci�n Cardiovascular de la SAC
Experto en Lipidos de la Sociedad Argentina de Lipidos.
Miembro de la Sociedad Argentina de Lipidos.
Instructor de ACLS de la American Heart Association


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