Hello,


I'm using Stata for the first time and encountered some difficulties. I'm working with Stata 15.1, and I aim to compare 2 groups of mammographers' true and false positives when reading mammograms; the control groupe did not undertake a teaching course and the test groupe did. I have results of their readings from 2010 to 2018, the course having happened in 2012.

At this point I should apologise in advance for the potential missing informations or wrong formulations, I'm not familiar with statistics or statistic-related softwares at all.

Now my approach is the following : I'd like to create a variable calculating the proportion of FP (false positives) and TP (true positives) for each one of them and for every year. My dataset includes 850,000 mammograms and to each one of them is associated one mammographer; now I obviously don't have 850,000 mammographers but merely 150. I need to ask Stata to create a variable indicating the total number of mammograms read by each mammographer for every year.

And unfortunately, I have absolutely no clue how to do this (even after a whole evening of trying). I already have the variables FP and TP for each mammogram.


I'm sure you'll need more details so please feel free to ask me !


Thanks in advance


A.G.