[R-meta] Proportional meta-analysis

[Viechtbauer Wolfgang (SP)]

Dear Ahmed,

See my comment below.

>-----Original Message-----
>From: R-sig-meta-analysis [mailto:r-sig-meta-analysis-bounces at r-
>project.org] On Behalf Of Ahmed Tarek
>Sent: Friday, 09 February, 2018 20:46
>To: r-sig-meta-analysis at r-project.org
>Subject: [R-meta] Proportional meta-analysis
>
>Dear All,
>
>In a previous email I have been explaining about a proportional meta
>analysis I have been performing. I am working on comparing the retention
>rates of different materials. I first took the approach of grouping
>different materials with similar follow up times , and calculating a
>summary proportion of all materials, however I later found out that
>performing a moderator analysis ( in this case “materials”) would only
>compare the materials against the summary proportion (?) , which is not
>my aim. I aim to see how each material performed, and compare directly
>between them. For example, I have materials A,B,C,D and I wish to compare
>the retention between A and B, to see if they are significantly
>different.

But this is exactly what a moderator analysis will do. Fit a single model to all outcomes, using 'materials' as a moderator. One level of the 'materials' factor will become the reference level to which all other levels are compared. Using contrasts, you can then also compare all other levels against each other.

Best,
Wolfgang