LCA with Covariates, Distal, and Impu... PreviousNext
Mplus Discussion > Latent Variable Mixture Modeling >
Message/Author
 James Swartz posted on Thursday, May 25, 2017 - 9:30 am
I am running an LCA with 19 binary predictors and an N of 223. The best fitting model has two classes (entropy = .87). I have regressed this model on three covariate predictors. I am fine with and, in fact, want the predictors to influence class membership.

Model:
%Overall%
c#1 on catag2 k6cat aids_eve;

My questions:

1) These predictors reduce the N to 189 so I have rerun the model using multiple imputation. Using MI, I can't get the conditional probabilities of the indicators, only thresholds. Is there a way to get the results in probability scale?

2) I have two binary outcomes included using the auxiliary statement. Mplus won't run these using DCAT, which I use because I want odds ratios for the distal variables. What other option works?

3) I want to regress the distal outcomes the covariates to obtain direct effects (as well as the indirect effects through latent class), how is this specified in the model statement?

Once the model is running on non-imputed data, can I run the exact same model using imputed data? I presently get this error message for the imputed data:

Auxiliary variables with E, R, DU3STEP, DE3STEP, or BCH are not available for TYPE=IMPUTATION.

Thanks for any help.
 Bengt O. Muthen posted on Thursday, May 25, 2017 - 6:44 pm
By 19 binary predictors I assume you mean 19 latent class indicators.

1) No auto in Mplus but you can easily compute them by the usual translation from logits to probabilities.

2) See the tables at the end of web note 21

3) In the 1-step approach you simply say y ON x in each class.

Last question - the message correctly states that this is not provided in Mplus.
 James Swartz posted on Friday, May 26, 2017 - 12:16 pm
Thank you Dr. Muthen,

I did mean indicators...sorry.

With respect to number 3, perhaps I was unclear...

In the current statements I have

usevar ind1-ind19 age aids;
auxiliary (e) hospital er;

Then in the model statement, as indicated, I have:

%Overall%
c#1 on age aids;

If I then add to that statement (as I interpreted from your suggestion):

hospital on age aids;

I get this error message:

*** ERROR in MODEL command
Unknown variable(s) in an ON statement: HOSPITAL

If I try to include hospital on the usevar AND auxiliary command, I get the same error message.

In other words, it seems to be telling me I can't have a variable that is defined as a distal outcome on the auxiliary command and also include that variable in the model as a DV regressed on one (or more) of the covariate predictors of latent class.

Is there a way to do this?
 Bengt O. Muthen posted on Friday, May 26, 2017 - 5:46 pm
First, note that Auxiliary (e) is outdated - see the tables at the end of Mplus Web Note 21.

To add that direct effect you have to take "a manual" approach to 3-step as discussed in Web Note 15 and 21.
 James Swartz posted on Friday, May 26, 2017 - 5:56 pm
Thank you again. Understood.
Back to top
Add Your Message Here
Post:
Username: Posting Information:
This is a private posting area. Only registered users and moderators may post messages here.
Password:
Options: Enable HTML code in message
Automatically activate URLs in message
Action: