I am doing a segmented poisson regression to look at counts pre- and post- an intervention. There is therefore a poisson regression line pre-intervention and post-intervention. The delineation is by week - 141 weeks total, the break point is week 105. I can create a variable ("preintervention") and code it as 1 if week < 105 and 0 if week >=105.   I want to graph the poisson regression lines pre- and post- intervention. The overall regresson would be: proc genmod data=have; model count=week / dist=poisson link=log; run;   My questions is - how do I transform this into a visual graph (presumably using proc sgplot) that will divide into 2 separate poisson regression lines - 1 pre intervention and 1 post.   Thank you for any assistance!       ... View more