Vera posted on Wednesday, November 06, 2013 - 6:01 pm
I am running an ordinal logistic regression, observed variables only, and need to test the significance of 4 mediators. I am new to Mplus and would like to make sure I am inputting and interpreting things properly.
1. Does this part of the input look correct? categorical = Y; ANALYSIS: bootstrap=10000; Model: M1 M2 M3 M4 on X c1 c2 c3 ; Y on X M1 M2 M3 M4 c1 c2 c3 ; MODEL INDIRECT: Y IND M1 X ; Y IND M2 X ; Y IND M3 X ; Y IND M4 X; output: CINTERVAL (BCBOOTSTRAP);
2. In order to see whether the total indirect effect and specific indirects were significant, I need to look at CONFIDENCE INTERVALS OF TOTAL, TOTAL INDIRECT, SPECIFIC INDIRECT, AND DIRECT EFFECTS, right? Thanks in advance!
1. The best way to check an input is to run the analysis and see if you get what you expect.
2. You can look at the p-value for the z test or at confidence intervals.
Jetty posted on Thursday, November 07, 2013 - 6:39 pm
Thanks, Linda. I am puzzled by a slight discrepancy between the CIs for the indirect effects and actual p-value for the z test. I have one effect for which p=.137 but the 95% CI (I am looking at lower and upper 2.5%) do not include 0 (lower 2.5%=.001 and upper 2.5%=.015). Am I missing something? Thank you
These should be the same for symmetric confidence intervals but not for BOOTSTRAP and BCBOOTSTRAP confidence intervals.
Jetty posted on Thursday, November 07, 2013 - 9:23 pm
Thanks, symmetry was the first thing that came to my mind as well. I will report the CIs as they result from bootrapping.
Jetty posted on Friday, November 08, 2013 - 1:44 pm
Dr. Muthen, I ran the model from my first post without ANALYSIS, MODEL INDIRECT, and OUTPUT commands because I wanted to get the fit indices for it, as I saw recommended on this board. The estimator is still WLSMV, parametrization DELTA, WRMR is identical, but some of the SE for the parameters and their associated p value differ. Why is that? Thank you
Jetty posted on Friday, November 08, 2013 - 2:43 pm