Currently, the Twitter API allows one to capture data on the number of likes, retweets, and replies for each tweet. However, this does not represent total engagement as it is missing data such as link clicks, profile clicks, detail expands, etc.
In order for researchers to understand what tweets gain most engagement, it is crucial to get the 'Total Engagement' data and impressions data for each tweet. This will help researchers understand specifically what type of content gets the highest engagement and accordingly tailor health messages.
Thanks for your feedback.
We are currently developing more simple and scalable ways for developers to get back impression and engagement data on their owned content. Check out this space for more information soon.
More detail is included in our Developer Platform Roadmap: https://trello.com/b/myf7rKwV/twitter-developer-platform-roadmap
Sajjad Fazel commented
You mentioned "We are currently developing more simple and scalable ways for developers to get back impression and engagement data on their owned content."
However, I am saying it would be valuable for researchers to have impression and engagement data from all public Tweets not just their own content.