Add AUCs

You're right. Let me rephrase the question:
How can I add AUCs from multiple studies into one summarized AUC. This would indicate the accracy for the diagnostic test used in these studies (assuming no bias I suppose). The aim is to compare diagnostic tests by summing studies grouped by test method.


Less is more. Stay pure. Stay poor.
Lots of questions.

Area for under the curve is based on a threshold, did all studies have the same threshold or was the threshold based on a composite of variables?

Do you suspect heterogeneity between studies (random effects)? Was disease risk (prevalence) comparable?

Side note, I believe that I have read that the pooling of AUC values is not always recommended, many times people will focus on pooled sensitivities and specificities. Readme v1.3 May 2012.pdf
But is it not so that AUC is considering alla possible tresholds?
Heterogeneity might be a problem. I haven't considered that yet. So, yes I need to address heterogeneity sooner or later.
Thanks, I will look into what is recommended regarding AUC pooling.


Less is more. Stay pure. Stay poor.
The receiver operator characteristic curve plots the sensitivity (y-axis) against 1-Specificity (x-axis) for a continuous variable. So yes it has all cut-offs for all continuous values in the dataset. Though, I have never seen a study make all that information available. You would have to have their raw datasets to do that. Most of the time studies present just the optimal cut-off value that maximized the AUC. If multiple studies do this, you may need to make sure they are all using the same cut-off (threshold) and that some of the study aren't controlling for other variables than others.