Sizing a Trial

[cardypen]

Hi! Is there a way to reproduce the "Size a Trial" functionality from Java in R?

[brandon-gallas]

We could create a function to reproduce the "Size a Trial" functionality. Unfortunately, we haven't had the capacity to create these tools (changed priorities and fewer staff), and the agency has limited our ability to publish our work. Things are starting to look better, slowly.

I have a collaborator who is working on an R markdown demonstrating how to size an MRMC trial for percent correct. We hope to share that this fall with an update to the iMRMC documentation.

I can point you to the supplementary materials from the VIPER study. The R markdown and associated pdf outline how I sized the VIPER study.

If you develop a function or R markdown file demonstrating how to size a trial, I would be happy to consider including it in the updated documentation, acknowledging your authorship, of course.

[brandon-gallas]

In addition to sizing analysis, I see an email from you also asking:

• Is there an existing library that can calculate moments directly from OR or RMH parameters?

The relationships are spelled out in this paper:
[1] B. D. Gallas, A. Bandos, F. Samuelson, and R. F. Wagner, “A framework for random-effects ROC analysis: biases with the bootstrap and other variance estimators,” Commun Stat A-Theory, vol. 38, no. 15, pp. 2586–2603, 2009, doi: 10.1080/03610920802610084.

You should also be able to deduce the relationships from the iMRMC code. I apologize that I just don't have the time to do this for you, but I would encourage you to share such a tool with me, and I will consider adding it to the iMRMC package, acknowledging your authorship.

[cardypen]

Thank you so much for sharing those resources and for taking the time to answer my questions. I am working on building tools to handle these scenarios and would be happy to share as I make progress.