I have computed a difficulty score for a range of vision tasks and want to see if there is a difference in the mean score by self-rated overall health (scored from 1 – 4). Following is what I used:
Sort overall_hlth
by overall_hlth: ci diff_score
This gives me the mean difficulty score and it’s CI for each of the 4 self-rated overall health groups. What command do I use in Stata to adjust the CI for age given that I think age affects both the difficulty score.
