Slide ten of these pdf slides indicates rules of thumb for assessing positive and negative likelihood ratios to evaluate them to assess discrimination of the model.
where
Positive likelihood ratio = Sensitivity / (1 - Specificity)
Negative likelihood ratio = (1 - Sensitivity) / Specificity
The slides also briefly mention Hierarchical ROC curves which are useful for plotting curves combining within and between study variances from studies in meta-analyses.
Reference
Jaeschke R, Guyatt, GH and Saclett DL (1994) Users guides to the medical literature. III. How to use an article abotu a diagnostic test. B. What are the results and will they help me in caring for my patients? The Evidence-Based medicine Working Group. Journal of the American medical Association, 271(9), 703-707.