ting hlin posted on Wednesday, June 08, 2011 - 7:42 pm
Hi: i have a Category independent variable area (1=urban, 2 rural, 3 other), i run the models treating the variables as continuous varaibes, it converged, but i have trouble interpreting the results. then i tried 2 (1 v.s. 2 & 3) or 3 categories dummy coding for variables "area", it did not converge. i have specified number of iterations already. how should i handling the probelm?
I am having difficulties with my dummy-codes on a TYPE = TWOLEVEL COMPLEX design.
My binary dependent variable is HAVEINS and my independent categorical variable is race_eth [Hispanic(1), white(2), Black(3), other(4)]. The frequencies for HAVEINS by race/ethnicity show that non-Hispanic white have the highest rate.
I dummy-coded 3 Race variables in SAS(Ref. white)using the example below and also verified they all matched the original variable:
If race_eth = 1 then hispanic = 1; else if race_eth = 3 or race_eth = 4 or race_eth = 2 then race_eth = 0; else race_eth = -999;
When I run my model: HAVEINS ON hispanic black other; OUTPUT: CINTERVAL;
The result indicate that Hispanic have higher rates of insurance, which is the opposite of what the frequencies show.
To address this issue I decided to use the DEFINE command in Mplus:
DEFINE: IF (race_eth == 1) then hispanic = 1; IF (race_eth /= 1) then hispanic = 0; IF (race_eth == 3) then Black = 1; IF (race_eth /= 3) then Black = 0; IF (race_eth == 4) then other = 1; IF (race_eth /= 4) then other = 0;
My questions are:
1)Am I using the DEFINE command correctly?
2)Are the dummy-variables created using DEFINE matching the ones I created in SAS?