There exist several criteria for assessing the quality of evidence in medical research articles. I am looking for a data set listing medical research articles along with some notation assessing the quality of the evidence given in the article.
E.g.: article X used randomized controlled trials with sample size 200 and no comparison with placebo.
I am mostly interested in medical research articles that study the impact of drug X or medical treatment Z on medical condition Z.
A few years ago I spent months trying to find a dataset like the one you're requesting. The closest thing I found was a literature search tool called The Trip Database (https://www.tripdatabase.com/). It's not really what you want--i.e., no specific evidence quality notation is available on the results--but you might ask the developer, Jon Brassey, if he has data that he's annotated for the tool's back-end use (for supervised machine learning training, etc.).
Good luck! And please update your answer if you find something, I'd love to see such a dataset myself.
