Difference-in-differnce with zero inflated data

mag_newbie — Thu, 11 Jun 2020 15:51:06 GMT

Hello everybody,

I did a differnce-in-difference anlysis for in health care expenditures using proc genmod and %NLEstimate. People participating in a stuctured health care programme (Prog=1) were compared to those who do not participate (Prog=0). With data for both groups availabe for 1 year before intervention (post=0) and 1 year after intervention (post=1). The same subjects are measured before and after. The code I used works for the primary outcome "total cost". But now I need to analyse subcategories of costs, additinally (for hospitalisation, drugs,...) and some of these subcategories are zero-inflated.

Is there any option how I can make a DiD anaysis using zero-inflated data?

Any help would be greatly appreciated.

Maggie

proc genmod data= cost; class prog post / ref= first; model total_cost= prog post prog*post / dist=gamma link=log; estimate "diff_in_diff" prog*post 1 -1 -1 1; lsmeans prog*post / e linik; lsestimate prog*post "diff_in_diff" 1 -1 -1 1; store out= gammod; run; data difdif; input k1-k4; set=1; datalines; 1 -1 -1 1; %NLEstimate (instore= gammod, label= Diff in Diff f=(exp(b_p1+b_p2+b_p4+b_p6) - exp(b_p1-b_p4)) - (exp(b_p1+b_p2) - exp(b_p1)), title= DiD Totel cost)

topic Difference-in-differnce with zero inflated data in SAS Enterprise Guide

Difference-in-differnce with zero inflated data